The odd thing to me about Nicholson is that the crappier the movie, the better he is. The complete lack of subtlety just doesn't work in a "real" movie. I'd say Five Easy Pieces and One Flew Over the Cuckoo's Nest were his peak, unfortunately. His best appearances since then have been on the Laker's sidelines...
He was really good in About Schmidt.
Yeah, I'll admit I liked that one.