Billionaires Warren Buffett and Bill Gates agree on the best business book ever written

Bill Gates and Warren Buffett.
Lacy O'Toole | CNBC

When Bill Gates first met long-time friend Warren Buffett in 1991, he asked for a business book recommendation.

Without hesitation, the Berkshire Hathaway CEO offered up his favorite: "Business Adventures," by John Brooks.

"More than two decades after Warren lent it to me — and more than four decades after it was first published — 'Business Adventures' remains the best business book I've ever read," Gates wrote on his blog in 2014. "John Brooks is still my favorite business writer."

It's not your typical business book.

Lemonis: The one book every professional should read
Lemonis: The one book every professional should read

A former staff writer for The New Yorker, Brooks compiled his 1969 classic using 12 stories from the world of Wall Street that originally appeared in the magazine.

Gates writes that, "Unlike a lot of today's business writers, Brooks didn't boil his work down into pat how-to lessons or simplistic explanations for success. (How many times have you read that some company is taking off because they give their employees free lunch?)"

"You won't find any listicles in his work. Brooks wrote long articles that frame an issue, explore it in depth, introduce a few compelling characters, and show how things went for them."

While a lot has changed in the business world since the 1960s, the fundamentals of building a strong business have not, Gates writes, adding, "Brooks's deeper insights about business are just as relevant today as they were back then."

As for the key takeaway?

"There's an essential human factor in every business endeavor," writes Gates. "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."