I don't like Sean Penn. I think he's an asshole. Even if he wasn't famous and given a soapbox to preach from, I'm sure that I would still dislike him (although I do love seeing him punch and kick Paparazzi, because Paparazzi are worse than AIDS). But in "State of Grace," Sean Penn is fucking awesome. And since I respect awesome, I tolerate his shit and still watch some of his movies.
Then there's Gary Oldman. Well, watching Oldman play Jackie Flannery is like watching God stretch a double into a triple. Magic, I tell you, pure magic.