Heath Ledger turned up, did that, and now every comic book villain is just trying to keep up.
Fun fact: "Heath Ledger locked himself in a hotel room for six weeks to develop the Joker's voice and mannerisms."
A film about a bloke who just wants his rug back, and honestly that's a cause worth fighting for.
Fun fact: "The word 'dude' is spoken roughly 160 times in the film, about once every 45 seconds."