NET WORTH: $11 billion For No. 4 on the Buffett/Gates list, the billionaire visionaries had to reach down to No. 23 on the Forbes list to buyout king Perelman, with an estimated net worth of $10 billion. Perelman has made his fortune in everything from cosmetics to television -- as long as the companies are distressed and ripe for a buyout specialist. Never far from the headlines, Perelman has been as famous for his marriages (most recently to actress Ellen Barkin) and his support of Jewish causes, as he has been for his turnaround of underwater companies like Revlon. Perelman is constantly on the list of the biggest donors among America's richest, even being profiled by Fox News talking head Bill O'Reilly for his charitable giving. Perelman has made large gifts to hospitals, in particular, though he has cast a wide net in his giving -- estimated to have surpassed at least $200 million in the past decade -- providing funding for arts institutions like Carnegie Hall and the Guggenheim Museum, medical research foundations like the Michael J. Fox Foundation for Parkinson's Research, and the World Trade Center Memorial Fund.