7. Jon Stewart
When Jon Stewart took over The Daily Show in 1999, his career wasn't exactly in the best place. His brief run as the host of MTV's The Jon Stewart Show didn't exactly set the world on fire, and movies like The Faculty and Playing by Heart weren't about to make him into a major Hollywood star. But he was amazing on The Larry Sanders Show, and the folks at Comedy Central were very wise when they chose him to succeed for Craig Kilborn. It took a couple of years, but he eventually turned The Daily Show into one of the funniest programs on television and a great platform for authors, congressmen and even presidents to speak directly to younger viewers. We're crushed that he's stepping down in August.