9. Daniel Gilbert
Net worth: $3.9 billion
Daniel Gilbert made his billions as the chairman and founder of Quicken Loans Inc and is the majority owner of NBA franchise the Cleveland Cavaliers, having taken complete control in 2005.
The 51-year-old rose to public prominence in the wake of LeBron James' move from the Cavs to Miami Heat in 2010, and was fined $100,000 by the NBA for his comments about the player.