Billy Bob Thornton in Sling Blade... just the way he was able to totally transform is an amazing thing. Eric Roberts in Star 80 makes me hate Eric Roberts because his character is such an asshole. Good stuff.
Daniel Day Lewis & Gary Oldman in everything. Val Kilmer in Tombstone (for hamming it up). Christian Bale in American Psycho. Too many to list. My all-time favourite is probably Christoph Waltz as Col. Hans Landa in Inglourious Basterds. Astonishing performance.
I was watching American Psycho yesterday. I forgot how funny that movie was, too. Bale was great. [video=youtube;8WdEL8DzvaM]http://www.youtube.com/watch?v=8WdEL8DzvaM[/video]
There isn't an actor in the world who pulls off the millionaire playboy, yuppie jack ass better than Bale.