When most people think of Warren Buffett, they picture timeless investing wisdom and decades of market-beating returns. Yet, in a revelation that often surprises many, Buffett says his greatest investments weren’t stocks, bonds, or even businesses.In his 2010 annual letter to Berkshire Hathaway’s shareholders, Warren Buffett called his home “the third best investment" he ever made, after his two wedding rings. The market expert still lives in the five-bedroom, 6,570 square-foot stucco home he bought for $31,500 in Nebraska, US, back in 1958. What tops Buffett's list of best investments?Buffett got married twice. The American investor married Susan Thompson back in 1952. After Susan’s death in 2004, he married Astrid Menks in 2006. The billionaire has repeatedly claimed his wedding rings and marriage licenses are the best investments in his life.Benjamin Graham’s book ‘The Intelligent Investor’Later in 2013, Buffett, in his annual letter, said that his mentor Benjamin Graham’s book ‘The Intelligent Investor’ was one of his top investments. “I can’t remember what I paid for that first copy of The Intelligent Investor. Whatever the cost, it would underscore the truth of Ben’s adage: Price is what you pay, value is what you get. Of all the investments I ever made, buying Ben’s book was the best (except for my purchase of two marriage licenses),” he wrote.Back in 2000, Buffett told a group of MBA students at Columbia Business School that knowledge is like compound interest. “Read 500 pages like this every day. All of you can do it, but I guarantee not very many of you will do it,” he said, as quoted by CNBC.Who was Benjamin Graham?Buffett has repeatedly credited the book The Intelligent Investor by Benjamin Graham, whom he calls the father of value investing. Graham championed a disciplined approach centred on buying companies trading below their intrinsic value—businesses that offered high dividend yields, low price-to-earnings (PE) multiples, and strong long-term potential despite being overlooked by the market. His philosophy shaped Buffett’s own investment framework and continues to influence value investors worldwide.He also taught investing for many years at Columbia Business School, where one of his students was the now-billionaire Warren Buffett.Buffett's frugal lifestyleBuffett is known for his strikingly simple lifestyle and philanthropic values. The billionaire investor once treated fellow billionaire and Microsoft co-founder Bill Gates not at a fancy restaurant, but at his favourite McDonald’s — and that too using coupons.Notably, Buffett is a regular at McDonald’s. While the billionaire is often asked about the ‘secrets’ behind his long and successful career, one lesser-known detail is how the stock market plays a role in his daily breakfast routine.“One of the good things about this five-minute drive is that there’s a McDonald’s on the way,” he once revealed in a documentary, as cited by Business Insider. He explained how he decides which breakfast sandwich to buy. Every morning, Buffett tells his wife, Astrid, the exact amount of change to place in the centre cup holder of his car—typically $2.61, $2.95, or $3.17.“When I’m not feeling quite so prosperous, I might go with the $2.61,” Buffett said. “That’s two sausage patties, which I put together, and then I pour myself a Coke. $3.17 is a bacon, egg, and cheese biscuit. But if the market’s down this morning, I’ll pass on the $3.17 and go with the $2.95.”After buying his McDonald’s breakfast, Buffett eats it at his desk with a Coke. While prices have likely risen since the documentary was filmed, the logic remains the same.(Disclaimer: Recommendations, suggestions, views and opinions given by the experts are their own. These do not represent the views of The Economic Times)