I'm not usually a big fan of Stephen Colbert of Comedy Central's The Colbert Report (silent t's). But he had a brilliant night of parody as he used Bush's own style and political strategy against him at the White House Correspondents' Dinner. However, mainstream media seems to have missed the joke, leaving it to be reported mostly on blogs and alternative sources such as Salon. Now some media sources are saying he wasn't funny at all. You can find the transcript on Daily Kos as well as a link to the video, and judge for yourself.
My personal favorite, as it highlights one of Bush's qualities that most annoys me:
The greatest thing about this man is he's steady. You know where he stands. He believes the same thing Wednesday that he believed on Monday, no matter what happened Tuesday. Events can change; this man's beliefs never will.