Wouldn't disagree about best this year (but I haven't seen too many in the theater), but I highly disagree about the perfect ending. I just don't think we needed the secondary plotline (trying to avoid spoilers here) and I think it made the movie about 10 minutes too long. Not that I was bored, I just would have done it differently.
The one thing that is incontrovertible fact is that Heath Ledger was OUTSTANDING. His Joker is among the top 25 character performances I've ever seen.
Regarding the audio- I don't know if it was my theater or what, but I was very disappointed in the bass. Not that there wasn't a lot of it, but it seemed to be coming from up at my face along with the dialogue, and not up through my seat. At times it overwhelmed the soundtrack and the spoken words, and it was also mismatched. I cannot wait for the BD version so I can watch it at home.