Warren Buffett, chairman and CEO of Berkshire Hathaway, still lives in the same home he bought for $31,500 in 1958.

Berkshire Hathaway CEO Warren Buffett drinks a bottle of Coca Cola during at a trade show at the company's annual meeting in Omaha, Nebraska May 3, 2014. Rick Wilking/Reuters

Net worth: $60.7 billion

The "Oracle of Omaha" is one of the wisest and most frugal billionaires around. Despite his status as the third-richest person on earth, he still lives in the same modest home he bought for $31,500 in 1958, doesn't carry a cellphone or have a computer at his desk, and once had a vanity license plate that read "THRIFTY," according to his 2009 biography.

Buffett also has a decidedly low-brow palate, known not just for investing in junk-food purveyors like Burger King, Dairy Queen, and Coca-Cola, but also for filling up on them as well. The Buffett diet includes five Cokes a day, as well as Cheetos and potato chips.

At his annual shareholder's meeting in 2014, Buffett explained that his quality of life isn't affected by the amount of money he has:

My life couldn't be happier. In fact, it'd be worse if I had six or eight houses. So, I have everything I need to have, and I don't need any more because it doesn't make a difference after a point.