Paul Allen is the founder of investment firm Vulcan, and co-founder of Microsoft. Worth $17.8 billion, Mr. Allen ranked #26 on the Forbes 400, donating 1.7 percent of his worth last year. This $298 million was split between the Paul G. Allen Family Foundation to support arts, education, and social-service groups, and a $100 million pledge to establish the Allen Institute for Cell Science.

Elaine Thompson/AP
Paul Allen, Microsoft co-founder, also owns the Seattle Seahawks. He attended the game against the Chicago Bears, Sunday, Sept. 27, 2015, in Seattle.