Stephen Colbert
Followers: 2.1 million
Sample tweet: "An apple a day may keep the doctor away — but all these Macbooks are getting expensive."
As host of The Colbert Report on Comedy Central, Stephen Colbert never shies away from a witty one-liner. He quips about current events and follows up jokes on his nightly fake newscast. His 140-character musings are so influential that one about the Gulf oil spill — "In honor of oil-soaked birds, 'tweets' are now 'gurgles.'" — was the most retweeted text of 2010 (the message also included a link to a charity drive). "It's official: I've won Twitter," Colbert proclaimed on his show, as he accepted the first annual Golden Tweet award. Now if only he could get Comedy Central colleague Jon Stewart to write his own tweets.