Even though the film isn't that good.
Let me explain:
If you watched the film and cut out every Joker scene, apart from the fact it wouldn't make much sense, it would be the worst film I've seen this year.
Heath Ledger saved the film from being a very boring unfunny film by being the most gorgeous funny sexy SCARY (some people say, I didn't find him scary at all but I don't fear death so there you go) Joker any Batman film has ever had.
I absolutely love Heath Ledger, and I did before The Dark Knight, but I love him even more now.
When I read in the newspaper in January that he died I was on the tube with a mate and I just started crying; it was so heart breaking. If you don't know, he died from an accidental drug overdose (prescription drugs).
It's really a shame we've lost such an amazing actor.
The contrast of his two roles in Brokeback Mountain and in The Dark Knight really show what an actor he is.
I don't like Christian Bale as an actor, especially after his rubbish performance in The Prestige.