Incredible,
I recall only a couple weeks before, walking out of Wanted saying, "Movies these days are incredibly action packed with high budget special effects, but I'm feeling that the storylines are getting worse and worse from the days of the godfather and schindler's list"
Boy did The Dark Knight prove me wrong. There was a sufficient array of action, and amazing visuals, but there was a story to cement it. The dark and psychological feel to the movie really set it apart from the likes of Spiderman and Superman.
What truly makes Batman shine, in my opinion, is the fact that he's without a real super power. He is simply at the pinnacle of perfection and discipline, both in his body, and as a wealthy billionaire businessman/playboy. But Batman's flaw is his necessity to put on masks, and shift his persona, from Bruce Wayne, to Batman, and back. As it was stated at the end of Batman Begins, by Rachel, that "[Bruce] is just a mask, the real face is the one that the criminals now fear." The Dark Knight deals with this and the Joker, especially attempts to exploits this, by constantly trying to make Batman break his moral code (Which you will see 2-3 times in the Dark Knight, but I don't want to reveal now).
Overall, an excellent performance by the villians, and Bale.