97. Gabe Newell
Newell’s programming career took off thanks to his brother, an early Microsoft employee. Newell hung around his sibling so much that Microsoft CEO Steve Ballmer got tired of his distracting presence—and offered the Harvard student a job to make actual use of him: “I learned more in 3 months working with those guys at Microsoft than I did the entire time I was at Harvard.” He dropped out of Harvard in 1983. Thirteen years later, he and another Microsoft alum cofounded videogame developer Valve Corp., a force in online PC game sales thanks to its successful digital store, Steam.