I think many people watched it but no one here to talk about it...
1st of all, it's a long movie so go to toilet before watching. It's long but pretty intense, there's some laughting points in the middle but it packed with many things (drama, action).
Heath Ledger was amazing, very intense and scary. He carried the character very well through out the whole movie. Compare to him, the hero Batman seems like a 50% off deal from Batman Begins.
Aaron Eckhart was great too, not as shiny as Joker but he played it just right as Harvey Dent.
Other than the three main characters and Lt. James Gordon, others were just a blur to the story.
Go watch it and make sure you watch it in a theater with good sound system. It worths every penny.
P.S. there goes my 1000th post...