First off, I think Heath Ledger did a fantastic job as the Joker.
He was frightening and almost unrecognizable as the mad clown prince of crime and perfect foil for the famous caped crusader.
All that said, I thought it was an Oscar winning performance.
Sure, I'm probably in the minority, but I don't think it was all that much of a stretch for someone with his talent to dive into a role like that.
The guy was a talented actor chewing on the scenery and did a damn good job at it.
How is that any different that what Johnny Depp did in any of the "Pirates of the Caribbean" flicks?
I would argue Ledger showed his Oscar winning acting chops in 2005's "Brokeback Mountain," not in "The Dark Knight."