I have seen previous Heath Ledger performances but none can even come close to his portrayal of the Joker. From his mannerisms, to his voice, to his costume and makeup, he literally BECAME the joker in this film. I am quite certain there will never be another villain performance that will come anywhere near the level this blessed, talented actor took it to.
On a side note, I feel Christian Bale's voice was bit too raspy but played the character well.
Also, two-face was a good role, however, the makeup seemed a bit extreme. They portrayed the different layers in the face and the muscles extremely well, however I feel as though they could have taken it back a notch to make it look more realistic.
Overall, one of the best films I have seen in years. Much credit goes to Heath Ledger for his character role, but the entire cast acted very well together to create an unforgettable summer blockbuster.