Heath Ledger is often mentioned as the best actor to portray the biggest enemy of Batman, The Joker. Maybe it was because he used method acting and let the character overrun him. Heath Ledger would practice method acting regularly and to turn into The Joker he locked himself away for weeks to catch the insanity of the character.

He even asked his co-star Christian Bale to actually hit him during the interrogation scene. Christian remembers, "He was slamming himself around, and there were tiled walls inside of that set which were cracked and dented from him hurling himself into them. His commitment was total."