This was one of the best superhero movies I've seen in a LONG time. It's worth seeing this movie just for Ledger's performance as The Joker.
Ledger leaves us with one hell of a final performance, and this is honestly going to be difficult for the franchise to top in the next installment. (Honestly, as far as superhero movies go, the only serious competitor I can see for the foreseeable future will be The Watchmen).
There's a ton of action and lots of new Bat-gadgets for Bale to play with. It would have been nice to see one of the subplots left open for expansion in another installment, but overall this is the first must-see movie of the summer.