I finally saw this Yesterday.
First off, we rewatched Batman Begins on Saturday on our projector (for the theater experience). Contrary to my first viewing at the drive-in, I really liked this movie. I wanted to have a clear viewing in mind for when we saw Dark Knight.
As for the Dark Knight, I bestow upon it the best compliment I can give a film:
Unlike most other films, I can honestly say that I saw no faults to the movie. It is as close to 'perfect' as a movie can be.

The voice did not bother me - it was more irritating in Batman Begins. He was also obviously out of breath in the movie doing the voice, and it really does make sense that he would talk that way.
Heath Ledger was simply amazing as the Joker. There is no doubt in my mind he deserves a post-humous Oscar. If he were simply playing a deranged psycho that wore makeup instead of "The Joker(TM)", it wouldn't even be up for debate.
Oh, and the pencil trick? That was ---smurfing--- awesome! I knew at that point that Ledger definitely deserved all the praise he was given, even if I didn't see another second of the movie.