He was very good in The Dark Knight though - even better in Brokeback Mountain. Two contrasting roles and performed extremely well by such a young guy. His death may have created a bit too much hype and I feel that, unfortunately, the quality of his work will always be doubted because of it.
I agree - BM was his best performance. His profound ability to immerse himself emotionally into those roles is rare for an actor so young, although I think people claiming that he died as a result of playing the Joker is silly - perhaps explains the hype though.
Also thought he was brilliant in Candy, although I prefer Requiem For A Dream and Transpotting as films in that genre.