While its fun to watch these clips of David Letterman sticking it to the man (Bill O'Reilly), and telling the Spinmeister, "I get the feeling that 60% of what you say is full of crap", its a shame that the clips leave out the rest of the exchange...
"Halfway through the exchange Letterman got himself into a corner, conceded he was not smart enough to argue his case but darted out, through a wall of O'Reilly noise, that he thought 60% of the Factor man's usual speechifying was 'crap'. O'Reilly demanded proof. Letterman found no better answer than: I don't watch your show. He was toast ever since."
Surprisingly, this comes from the uber-liberal Talking Points Memo - read the rest here.
To be fair, I think I could better argue that only 10% of what O'Reilly says is crap (a good 2% comes from whenever he tells a guest he'll give them "the last word", but adds a line of commentary after).