21. Paul allen
$20.3 billion Self-made Score: * Source: microsoFt, investments age: 65 reSidence: mercer island, Wa PhilanthroPy score: The Microsoft cofounder spends his time on his sports empire—which includes the Portland Trail Blazers and Seattle Seahawks—and philanthropy. To date, Allen, who left Microsoft after just 8 years when he was diagnosed with Hodgkin’s disease, has given more than $2.5 billion to charity. His eclectic causes include preserving endangered wildlife, understanding the human brain and supporting art festivals. His Stratolaunch plane, the largest aircraft ever built, is designed to launch rockets while the plane is in flight.