O.k., let's clear the air first. I loved the Jack Nicholson version of the Joker. He was simply amazing. But I really enjoyed Ledger's take on the role and liked it even more. Mainly, it's due to the way he came across as utterly crazy. He plays the Joker very intelligently, but totally off his rocker at the same time, which is a very dangerous combo.
This latest rebirth of the Batman movie is definitely my favorite. While the 80s film by Tim Burton will always hold a place in my heart, I really think this is closer to the original stories, which I really like about them.
Bale is, again, great at playing Bruce Wayne and the rest of the cast is wonderful, as well, especially Eckhart as Harvey Dent, and Caine and Freeman as Wayne's closest compadres.
I adore Maggie Gyllenhaal, so seeing her instead of Katie Holmes was a nice treat (not that I disliked Holmes, but I just like Gyllenhaal more) and I thought she did a really nice job with her role.
The storylines were brilliantly put together and now, more than ever, I mourn the passing of Ledger since it means we won't get to see this iteration of the Joker again.
All in all, an extremely good movie, sequel or not.