At $67 billion, Bill Gates takes the No. 2 position in the overall countdown, as well as our tech group. In case you're new to the planet, Gates had something to do with the formation of some company called Microsoft. But more recently, he's been focused on philanthropy, particularly in the area of fighting diseases including polio and malaria. According to Forbes, Gates already has donated more than $28 billion to various social causes. He's also combined philanthropic forces with various other folks on the Forbes list, including Sir Richard Branson and Carlos Slim Helu, with whom he funded a new $25 million agricultural research center in Mexico. The publication quotes Gates as saying that the only thing left on his bucket list is, "Don't die." But we're not sure money can buy that concession.