The chief executive officer of Microsoft since January 2000, a company which he's very proud of being part of. He likes to express this by yelling, running or dancing on stage, making faces, and jumping out of a cake.
In the 1999 documentary/drama Pirates of Silicon Valley, his character is played by actor John DiMaggio, who's well known for providing the voice for Bender from Futurama and Marcus Fenix of Gears of War fame.
As of 2011, his personal wealth is estimated at US$14.5 billion, ranking number 46 on the Forbes list of billionaires.
Famous Ballmer moments: