College dropout David Geffen made his money through Geffen Records, which signed top artists from Elton John to Nirvana. He co-founded film studio DreamWorks SKG and has also reportedly made hundreds of millions selling artworks. The 81-year-old, who came out in the 1990s, has donated to many causes linked to gay rights and AIDS. His property empire has been valued at $450 million (£352m), and he owns a 453-foot yacht.