10. Bill Gates
Bill Gates, co-founder and co-chair of the Bill & Melinda Gates Foundation, speaks during a health summit on November 9, 2010 in Washington, DC. Microsoft mogul, futurist and America's richest person has, with help from billionaire buddy Warren Buffett, convinced nearly 60 of the world's wealthiest to sign his "Giving Pledge," promising to donate the majority of their wealth to charity either during their lifetime or after death. He is no longer the planet's richest person, but that's because he's given away $ 30 billion to his foundation. (Photo by Mark Wilson/Getty Images)