It was okay. The plot was a little ridiculous. The movie a bit too long. The sound balance a bit off.
All in all I give the movie a solid 7 of 10.
Heath Ledger though, delivered everything promised. Even though his character wasn't quite where he could have been, Ledger's performance was incredible. He was creepy, crazy, brilliant, funny, scary, and never once appealing. He made the Joker a despicable, and incomprehensible lunatic. I'm rooting for that performance to get an oscar nod - it really did deserve it.
On a side note: will people in hollywood please, please, please stop hiring Maggie Gyllenhaal. Her droopy, sagging eyes coupled with her natural lack of charisma, sexiness, or class makes her just unbearable every time I see her in a film. Enjoyable movies such as The Dark Knight or Stranger than Fiction have been marred by her presence in them. I don't know who keeps saying "You know who would be great? That creepy girl from the movie Secretary. Let's hire her for a completely inappropriate role." Please, for the love of all that is good and decent on this earth, stop giving that woman work.