Let's just get this out of the way: Heath Ledger was brilliant as the Joker: mesmerizing, compelling, disturbing, brilliant right from the first disappearing pencil moment (when the entire audience jumped and sighed, "Oooooohhh"). One of the online reviews I've read said that the issue with the heretofore iconic Jack Nicholson/Joker portrayal is that it was clearly "Nicholson as the Joker." Not so with Ledger's performance: there was no Heath seeping through - he completely gave himself over to that maniacal agent of chaos and we all believed it. Whether his subsequent and sad death was due to his believing it too we'll never really know. But it's a damn shame we'll never be able to see him reprise the role.
Another one I believed: Aaron Eckhart as Harvey Dent. I don't read Batman comics so all I knew of the Harvey Dent character was Tommy Lee Jones's version (yeesh). Eckhart's Dent shone like an avenging angel bent on saving his tortured city. Beautiful, righteous and fearless, Dent's subsequent fall was all the more horrific because of his purity. And that nightmarish Two-Face make-up? Holy shit. I think that with all the commotion over Ledger and his Joker, the filmmakers were able to keep Dent's transformation under wraps to good effect.
In fact, the characters, their development and their convincing interactions with each other were my favorite thing about this movie - pretty remarkable for a blockbuster of this type. Gary Oldman continues to be incredible as
I guess the reigning presumption has been that Gotham City is a fictionalized version of NYC, but I gotta say that per director Christopher Nolan's vision, Chicago = awesome as Gotham. Chicago's got such a history that you can easily believe Gotham as a seething mass of corrupt cops, Italian mobsters, Russian, black and Asian gangsters all fighting for a piece of the pie.
All this being said, I didn't walk out of the theater thinking, omigodbestmovieever! It ran a little long, particularly towards the end; I had trouble with the editing of some of the action and fight scenes (too fast and jumbled to see what was going on); and Christian Bale's Batman-voice bugged the crap out of me. I understand the character's desire to disguise his voice for secrecy's sake but what was merely a deepening and gruffness in Batman Begins was way over the top in this movie. Nobody talks like that - not even Batman.
I did not, however, have a problem with the dark tone of the movie - I like dark stuff - and I think they did it the right way: these stories of the Joker and Harvey Dent and corruption do not lend themselves to puns and easy laughs. The Dark Knight proves that superhero movies do not have to be lighthearted to be good. Is it the best comic book movie ever? I don't know (I did walk out of Iron Man thinking, omigodsomuchfunthatwasawesome!) but The Dark Knight is on the short list for sure.