George Carlin 5

I saw him a few years ago and was amazed that after 40 years he still has such drive for what he did. He was unsurpassed in his ability to make an audience to think and laugh at the same time. He would say something jarringly provocative, then when you thought he should back off he'd wade further into the controversy. By the time he was done, you had laughed at yourself for being so uptight and found yourself thinking of things in a different light. He was a wordsmith on a par with any of the generation's great writers. He was rude, he talked dirty, but most importantly he was honest. 

http://www.youtube.com/watch?v=3PiZSFIVFiU