5. Ben Stiller
The comic actor showed his darker side directing 1994's Reality Bites and 1996's Cable Guy. By 2001, with Zoolander, he created a cult classic by skewering male-model posturing (Blue Steel, anyone?). And in 2008's Tropic Thunder, Stiller as director, co-producer, co-writer and co-star, showed us Hollywood at war with its own ginormous ego during the making of a megabudget Vietnam War epic with an uproariously inept cast and crew. Next up is Stiller's most ambitious project yet, as star and director of The Secret Life of Walter Mitty, from James Thurber's beloved story about a daydreamer.