Great acting, effects, and storyline through and through. Unlike some of the other Batman movies, there are no cheesy one-liners; the whole film possesses a dark and sinister tone that remains in your system until long after the movie is over. Heath Ledger delivers what is expected of him, and he brings the Joker's character back to a demented, deranged, creepy psychopath. Even the witty, sarcastic "Thank You For Smoking" star surprised me with his ability to transform the honest district attorney into the raging Two Face character.
There is so much more to say, but I'd rather let it all be a surprise. I want to see this movie again in the theater, and that doesn't happen often...