#59 Elon Musk of SpaceX
He's heard it before and he'll hear it again, so we might as well come out and say it: Elon Musk is real life's Tony Stark. With his high-end electric car company, Tesla, and its mainstream Model S sedan rolling out of its domestic manufacturing base in Fremont, Calif., Musk could take a long nap on his laurels. After all, Tesla could herald a new era for clean car manufacturing in the US.
But Musk's entrepreneurial zeal knows no bounds, driving him to found space-exploration company SpaceX, which sent its first operational flight of the Falcon 9 rocket into orbit this October. Musk predicts he'll send passengers into space for a mere $500,000 within 15 years and that life on Mars isn't out of reach. Suit up, Iron Man.
For more on this story, see Elon Musk's plan for life on Mars.