I've seen Wall-E and Dark Knight.
Wall-E was a fantastic movie, with very engaging characters (except for the humans).
Dark Knight was OK. Heath Ledger gave an outstanding portrayal of the Joker, but that's pretty much it for the movie. The action scenes were uninspiring, and for some reason I just want to punch Bruce Wayne in the face, especially when he does his "I've been smoking since the age of 2" Batman voice.
I expect something like Milk (praised by critics as "ass-rammingly good") or Frost/Nixon ("the greatest story of modern journalism ever told") will win. Hollywood doesn't care what movies are good, they care about political favoritism.
I don't really care one way or another which movie wins, it's a pretty meaningless award.