Paul Allen was a friend and high school classmate of Bill Gates, and together the two made history and a fortune founding Microsoft in 1975. Paul, known as the idea man, resigned from Microsoft in 1983 after being diagnosed with Hodgkin's disease. However, thanks to company stock, Allen earned billionaire status in his early 30s.
He also set up companies like Silicon Valley think tank Interval Research and Vulcan Ventures, which has a $2B portfolio that includes more than 6.6M SF of office, life sciences, residential, and mixed-use space, 80% of which is in South Lake Union, one of the largest urban redevelopment projects in the nation. Paul also owns the NBA's Portland Trailblazers and the NFL's Seattle Seahawks (worth $1.3B), and has an interest in the Seattle Sounders, America's most valuable major league soccer team, which is worth $175M.
<p>Location: Las Vegas | Net Worth: $25.20 B</p>