Me too! I had only started listening to him in June of 2004 but between the Bush-bashing and the Iraq War bashing, I couldn't stand listening to him anymore...
He comes across as an arrogant twit who gets all superior-acting, nasty, and sarcastic when people disagree with him.
Also, that "thank you" bit to those who serve(d) in the armed forces comes across as self-centered, like they're doing it for him.
He lost me when Jeannie Garafaolo (?) lost her show for vociferous disagreement with partial birth abortion, and his statements were that it's his job to do his thing and not to stick his neck out for others.