I'm sure there's nothing I can really say about the Dark Knight that hasn't been expressed elsewhere on the internets already, but I just have to say I loved it! No surprise there, right? It was a wonderful crime yarn (that just happened to have a few guys in costumes in it), the best Batman story (in live-action mind you) ever committed to film, and probably the best ensemble cast in any movie EVER. But that's just my two cents. Go and see for yourself, I hear they could really use the ticket sales;)
Since this one has already done so well maybe we'll be lucky enough to get a Commissioner Gordon spin-off film before they jump into another sequel. Give Christian Bale some time out of the rubber outfit to be in a Terminator movie or whatever, and get the real star of Dark Knight, Gary Oldman (who gave, in my opinion, the best performance in the film, in a role that he just completely disappears into) the top billing he deserves.
I honestly can't recommend seeing this move highly enough. Just don't finish off your soda too fast. This thing clocks in at over two hours and we don't need anybody poppin' a bladder in the theatre.