Stephen Colbert is a comedic genius of the highest order. His stint on the Daily Show had some of the best moments in the show's history. As great as he was on the Daily Show, the Colbert Report managed to be even funnier. His parody of right-wing television pundits such as Bill O'Reilly is one of the funniest things on TV today.
His off-screen life is just as funny. The White House Correspondent's Dinner he hosted was genius. His short-lived run for President was a much-needed spoof of the insanity of our election system. His book, I Am America (and so can you) is the funniest thing I've read all year.