Aside from a handful of novels, they're mostly nonfiction books covering his and his foundation's broad range of interests. A lot of them are about transforming systems: how nations can intelligently develop, how to lead an organization, and how social change can fruitfully happen.
Here are the titles he's given glowing reviews and that changed his perspective over the past several years.
'The Better Angels of Our Nature: Why Violence Has Declined' by Steven Pinker
In "Better Angels," Harvard cognitive scientist Steven Pinker branches out into the history of the most contentious of subjects: violence.
Gates says it's one of the most important books he's ever read.
"Pinker presents a tremendous amount of evidence that humans have gradually become much less violent and much more humane," he says, in a trend that started thousands of years ago and continued until this day.
This isn't just ivory-tower theory. Gates says the book has affected his humanitarian work.
"As I'm someone who's fairly optimistic in general," he says, "the book struck a chord with me and got me to thinking about some of our foundation's strategies."
'The Sixth Extinction: An Unnatural History' by Elizabeth Kolbert
"Humans are putting down massive amounts of pavement, moving species around the planet, over-fishing and acidifying the oceans, changing the chemical composition of rivers, and more," Gates writes, echoing a concern that he voices in many of his reviews.
"Natural scientists posit that there have been five extinction events in the Earth's history (think of the asteroid that wiped out the dinosaurs)," he continues, "and Kolbert makes a compelling case that human activity is leading to the sixth."
To get a hint of Kolbert's reporting, check out the series of stories that preceded the book's publication.
'The Man Who Fed the World' by Leon Hesser
Even though Gates can get a meeting with almost anyone, he can't land a sit-down with Norman Borlaug, the late biologist and humanitarian who led the "Green Revolution" — a series of innovations that kept a huge chunk of humanity from starving.
"Although a lot of people have never heard of Borlaug, he probably saved more lives than anyone else in history," Gates says. "It's estimated that his new seed varieties saved a billion people from starvation," many of whom were in India and Pakistan.
Borlaug was awarded the Nobel Peace Prize, the Presidential Medal of Freedom, and the Congressional Gold Medal for his efforts — and is one of only seven people to receive that honor.
For Gates, Borlaug is a model in getting important work done in the world.
"Borlaug was one-of-a-kind," he says, "equally skilled in the laboratory, mentoring young scientists, and cajoling reluctant bureaucrats and government officials."
Hesser's "The Man Who Fed the World" lets you peer into the personality that saved a billion lives.
'Business Adventures: Twelve Classic Tales from the World of Wall Street' by John Brooks
Back in 1991, Gates asked Buffett what his favorite book was.
To reply, Buffett sent the Microsoft founder his personal copy of "Business Adventures," a collection of New Yorker stories by John Brooks.
Though the anecdotes are from half a century ago, the book remains Gates' favorite.
Gates says that the book serves as a reminder that the principles for building a winning business stay constant. He writes:
For one thing, there's an essential human factor in every business endeavor. It doesn't matter if you have a perfect product, production plan and marketing pitch; you'll still need the right people to lead and implement those plans.
Learning of the affections that Gates and Buffett have for this title, the business press has fallen similarly in love with the book. Slate quipped that "Business Adventures" is "catnip for billionaires."
'The Vital Question' by Nick Lane
Nick Lane might not be a household name, but Gates want to change that.
"Nick is one of those original thinkers who makes you say: More people should know about this guy's work," he says. "He is trying to right a scientific wrong by getting people to fully appreciate the role that energy plays in all living things."
The book seeks to resolve unanswered questions about how life formed on earth, and raises thoughtful questions about where solutions for disease may come from.
"Even if the details of Nick's work turn out to be wrong," Gates says, "I suspect his focus on energy will be seen as an important contribution to our understanding of where we come from."
'String Theory' by David Foster Wallace
No, not that kind of string theory.
The book is a collection of essays from David Foster Wallace that all revolve around tennis — the late author's favorite game.
Gates says he's been trying to get back into the sport after some small professional matters (read: starting one of the world's largest tech companies and becoming a celebrated philanthropist) got in the way.
"You don't have to play or even watch tennis to love this book," he writes. Wallace "wielded a pen as skillfully as Roger Federer wields a tennis racket."
'The Heart' by Maylis de Kerangal
Though it may be a novel, "The Heart" is about as close to creative nonfiction as fiction gets, Gates says.
The story involves a man dying in an accident, after which his parents decide to donate his heart. "But the plot is secondary to the strength of its words and characters," Gates writes. "The book uses beautiful language to connect you deeply with people who may be in the story for only a few minutes."
The recommendation is courtesy of his wife Melinda, he says, and now he's passing it along to the public.
'How to Lie with Statistics' by Darrell Huff
Published in 1954, "How to Lie with Statistics" is an introduction to statistics — and a primer on how they can be manipulated.
It's "more relevant than ever," Gates says.
"One chapter shows you how visuals can be used to exaggerate trends and give distorted comparisons," he says. "It's a timely reminder, given how often infographics show up in your Facebook and Twitter feeds these days."
'The Bully Pulpit: Theodore Roosevelt, William Howard Taft, and the Golden Age of Journalism' by Doris Kearns Goodwin
Like us, Gates is fascinated by the way Theodore Roosevelt was able to affect his society: busting trusts, setting up a park system, and the like.
For this reason, Gates appreciates how Goodwin's biography uses the presidency as a lens for understanding the shift of society.
"How does social change happen?" Gates asks in his review. "Can it be driven by a single inspirational leader, or do other factors have to lay the groundwork first?"
He says that TR shows how many stakeholders need to be involved.
"Although he tried to push through a number of political reforms earlier in his career," Gates says, "[Roosevelt] wasn't really successful until journalists at 'McClure's' and other publications had rallied public support for change."
'How Asia Works' by Joe Studwell
Joe Studwell is a business journalist whose central mission is understanding "development."
The Financial Times said that "How Asia Works" is "the first book to offer an Asia-wide deconstruction of success and failure in economic development."
Gates says that the book's thesis goes like this:
All the countries that become development success stories (1) create conditions for small farmers to thrive, (2) use the proceeds from agricultural surpluses to build a manufacturing base that is tooled from the start to produce exports, and (3) nurture both these sectors with financial institutions closely controlled by the government.
'Tap Dancing to Work: Warren Buffett on Practically Everything, 1966-2012' by Carol Loomis
Warren Buffett and Gates have a famously epic bromance, what with their recommending books to each other and spearheading philanthropic campaigns together.
So it's no surprise that Gates enjoyed "Tap Dancing to Work," a collection of articles and essays about and by Buffett, compiled by Fortune magazine journalist Carol Loomis.
Gates says that anyone who reads the book cover-to-cover will walk away with two main impressions:
First, how Warren's been incredibly consistent in applying his vision and investment principles over the duration of his career;
[S]econdly, that his analysis and understanding of business and markets remains unparalleled. I wrote in 1996 that I'd never met anyone who thought about business in such a clear way. That is certainly still the case.
Getting into the mind of Buffett is "an extremely worthwhile use of time," Gates concludes.
'The Rosie Project: A Novel' by Graeme Simsion
Gates doesn't review a lot of fiction, but "The Rosie Project," which came on the recommendation of his wife, Melinda, is an oddly perfect fit.
"Anyone who occasionally gets overly logical will identify with the hero, a genetics professor with Asperger's Syndrome who goes looking for a wife," he writes. "(Melinda thought I would appreciate the parts where he's a little too obsessed with optimizing his schedule. She was right.)"
The book is funny, clever, and moving, Gates says, to the point that he read it in one sitting.
'The Myth of the Strong Leader' by Archie Brown
Two years ago, Oxford political scientist Archie Brown offered his theory that history's most effective leaders don't actually live up to the tough-as-nails stereotype. They aren't all "strong leaders."
Figures such as FDR and Nelson Mandela instead wielded a more discreet kind of power — mainly through their delegation and diplomacy. Given that Donald Trump won the most recent election largely for his perceived strength, Gates says Brown's book is incredibly relevant.
"Brown could not have predicted how resonant his book would become in 2016," Gates writes.
'Born a Crime' by Trevor Noah
Noah, host of "The Daily Show," recounts his experiences growing up with a black South African mother and a white Swiss father in apartheid South Africa in the late 1980s.
His book is equal mixture heartbreaking memoir and laugh-filled comedy, according to Gates, a self-admitted longtime fan of "The Daily Show."
"Much of Noah's story of growing up in South Africa is tragic," he says. "Yet, as anyone who watches his nightly monologues knows, his moving stories will often leave you laughing."
'Stuff Matters' by Mark Miodownik
If you're like most people, you use steel razors, glass cups, and paper notepads every day without thinking much about the materials they're made of.
In "Stuff Matters," Miodownik, a materials scientist, aims to show you why the science behind those materials is so fascinating.
That premise might sound similar to "Making the Modern World," a book by Gates' favorite author Smil, which Gates has also recommended. But Gates says the two works are "completely different." While Smil is a "facts-and-numbers guy," Miodownik is "heavy on romance and very light on numbers," potentially making "Stuff Matters" an easier read.
Gates claims his favorite chapter is the one on carbon, "which offers insights into one atom's massive past, present, and future role in human life."
'Hyperbole and a Half' by Allie Brosh
It might be hard to imagine Gates curled up with a book of comic drawings. But "Hyperbole and a Half," based on the blog by the same name, is more moving and profound than it is silly.
The stories and drawings in the book are based on scenes from Brosh's life, as well as her imagined misadventures.
"It's funny and smart as hell," Gates writes, adding that "Brosh's stories feel incredibly — and sometimes brutally — real."
Gates was especially moved by the parts of the book that touch on Brosh's struggles with severe depression, including a series of images about her attempts to leave an appropriate suicide note.
It's a rare book that can simultaneously make you laugh, cry, and think existential thoughts — but this one seems to do it.
'The Power to Compete' by Hiroshi Mikitani and Ryoichi Mikitani
Japan used to be an economic juggernaut, but today its output tends to live in the shadows of South Korea and China. "The Power to Compete" explores the country's fall from technological grace, which Gates says touches a soft spot for him.
Hiroshi Mikitani is the founder and CEO of Rakuten, one of the largest internet companies in the world. Together with his father, who died in 2013, the pair envision a future in which Japan is once again a thriving economic hub.
"Although I don't agree with everything in Hiroshi's program," Gates says, "I think he has a number of good ideas. 'The Power to Compete' is a smart look at the future of a fascinating country."
'What If?' by Randall Munroe
Another book based on a blog, "What If?" is a collection of cartoon-illustrated answers to hypothetical scientific questions.
Those questions range from the dystopian ("What if I took a swim in a typical spent nuclear fuel pool?") to the philosophical ("What if everyone actually had only one soul mate, a random person somewhere in the world?") Each question was posed by a different reader, and Munroe, a former roboticist for NASA, goes to the greatest lengths to answer it accurately through research and interviews.
The reason Munroe's approach is a great way to learn about science is that he takes ideas that everybody understands in a general way and then explores what happens when you take those ideas to their limits. For example, we all know pretty much what gravity is. But what if Earth's gravity were twice as strong as it is? What if it were three times as strong, or a hundred? Looking at the question in that way makes you start to think about gravity a little differently.
For anyone who's ever wished there were someone to indulge and investigate their secret scientific fantasies, this book comes in handy.
'Stress Test: Reflections on Financial Crises' by Tim Geithner
Gates stood at the center of an enormously complex system as CEO of Microsoft. Timothy Geithner did much the same as US Treasury secretary — and saw the structure fall down around him during the financial crisis.
"Geithner paints a compelling human portrait of what it was like to be fighting a global financial meltdown while at the same time fighting critics inside and outside the Administration as well as his own severe guilt over his near-total absence from his family," Gates says. "The politics of fighting financial crises will always be ugly. But it helps if the public knows a little more about the subject."
"Stress Test" provides that knowledge.
'On Immunity' by Eula Biss
Even though the science all says that vaccines are among the most important inventions in human history, there's still a debate about whether they're a good idea.
In "On Immunity," essayist Eula Biss pulls apart that argument.
She "uses the tools of literary analysis, philosophy, and science to examine the speedy, inaccurate rumors about childhood vaccines that have proliferated among well-meaning American parents," Gates writes. "Biss took up this topic not for academic reasons but because of her new role as a mom."
'Should We Eat Meat?' by Vaclav Smil
Gates isn't shy about proclaiming Smil, a professor emeritus at the University of Manitoba, his favorite author. In fact, he's recommended several of Smil's books before.
As usual, Gates writes, Smil attacks the issue of whether humans should consume meat from every possible angle. First he tries to define meat, then he looks at its role in human evolution, as well as how much meat each country consumes, the health and environmental risks, and the ethicality of raising animals for slaughter.
Gates, who was a vegetarian for a year during his 20s, is especially impressed by how Smil uses science to debunk common misconceptions, like the idea that raising meat for food involves a tremendous amount of water.
In fact, Gates writes:
Smil shows you how the picture is more complicated. It turns out that not all water is created equal. Nearly 90 percent of the water needed for livestock production is what's called green water, used to grow grass and such. In most places, all but a tiny fraction of green water comes from rain, and because most green water eventually evaporates back into the atmosphere, it's not really consumed.
Overall, the book left Gates feeling that eventually, "the world can meet its need for meat."
'Shoe Dog' by Phil Knight
Knight, the co-founder of Nike, released the first insider account of the world-famous retailer earlier this April.
Gates calls the book a "refreshingly honest" reminder that the road to success is never a straight line. It's a winding path rife with disagreements, fallouts, and hurt feelings.
"I've met Knight a few times over the years," Gates writes. "He's super nice, but he's also quiet and difficult to get to know. Here Knight opens up in a way few CEOs are willing to do."
'Epic Measures' by Jeremy Smith
Reading this biography was especially meaningful for Gates because he's known its subject, a doctor named Chris Murray, for more than a decade.
According to Gates, the book is a "highly readable account for anyone who wants to know more about Chris's work and why it matters."
That work involves creating the Global Burden of Disease, a public website that gathers data on the causes of human illness and death from researchers around the world. The idea is that we can't begin finding cures for health issues if we don't even know what those issues are.
Writes Gates: "As Epic Measures shows, the more we make sure reliable information gets out there, the better decisions we all can make, and the more impact we all can have."
'Making the Modern World: Materials and Dematerialization' by Vaclav Smil
Gates says his favorite author is Vaclav Smil, an environmental-sciences professor who writes big histories of things like energy and innovation.
His latest is "Making the Modern World." It got Gates thinking.
"It might seem mundane, but the issue of materials — how much we use and how much we need — is key to helping the world's poorest people improve their lives," he writes. "Think of the amazing increase in quality of life that we saw in the United States and other rich countries in the past 100 years. We want most of that miracle to take place for all of humanity over the next 50 years."
To know where we're going, Gates says, we need to know where we've been — and Smil is one of his favorite sources for learning that.
'The Grid: The Fraying Wires Between Americans and Our Energy Future' by Gretchen Bakke
"The Grid" is a perfect example of how Bill Gates thinks about book genres the way Netflix thinks about TV and movies.
"This book, about our aging electrical grid, fits in one of my favorite genres: 'Books About Mundane Stuff That Are Actually Fascinating,'" he writes.
Growing up in the Seattle area, Gates' first job was writing software for a company that provided energy to the Pacific Northwest. He learned just how vital power grids are to everyday life, and "The Grid" serves as an important reminder that they really are engineering marvels.
"I think you would also come to see why modernizing the grid is so complex," he writes, "and so critical for building our clean-energy future."
'Seveneves' by Neal Stephenson
After a science-fiction dry spell of more than a decade, in 2016 Gates picked up "Seveneves" on a friend's recommendation, and he says he's grateful for it. "The plot gets going in the first sentence, when the moon blows up," he writes.
But that's only the beginning. The world soon learns the entire species is doomed: In two years' time, a cataclysmic meteor shower will destroy all life on the pale blue dot. It's up to humanity to send as many spacecraft into orbit as possible with the hope of escaping the apocalypse.
"You might lose patience with all the information you'll get about space flight," Gates writes, "but I loved the technical details."
'A Full Life' by Jimmy Carter
After having written more than 24 books already, President Carter's memoir about growing up in the small town of Plains, Georgia still reads as a quick, impressive book, Gates writes.
"I loved reading about Carter's improbable rise to the world's highest office," he says. "The book will help you understand how growing up in rural Georgia in a house without running water, electricity, or insulation shaped — for better and for worse — his time in the White House."
The stories may be from another time, but Gates says they carry a distinct timeliness as people's trust in political institutions (and the people running them) are at near rock-bottom.
'The Gene: An Intimate History' by Siddhartha Mukherjee
Genome science can hardly be considered a topic of mainstream interest, but Gates says Mukherjee manages to capture its relevance to people's daily lives. He seeks to answer big questions concerning our personalities and what makes us, us.
"Mukherjee wrote this book for a lay audience, because he knows that the new genome technologies are at the cusp of affecting us all in profound ways," Gates writes.
Mukherjee is what Gates calls a "quadruple threat." He's a practicing physician, teacher, researcher, and author.