Avatar is a very average movie which rightly deserves accolades for technical achievement. But I found it very strange that the movie didn't have one memorable line of dialogue and not one scene where I felt invigorated, pumped up or moved. The Hurt Locker, while a very good movie, didn't quite strike me as Best Film material. 
I've only seen six of the nominations: A Serious Man, Avatar, District 9, Inglourious Basterds, The Hurt Locker and Up. Of those, I'd say I liked Up the best with Inglourious Basterds coming in second and District 9 a close third. A Serious Man, while a very artsy/obscure movie (the kind that critics and award shows like to honor) just isn't that memorable a picture. Good while it lasts, not exactly worthy of best film of the year. Hence that puts it fifth on my list behind The Hurt Locker.
Avatar wouldn't even be nominated if it didn't cost so much and didn't make two-and-a-half billion dollars.
Waiting to watch Up in the Air and An Education. I'll catch The Blind Side if fate has it in store for me, Precious flat out annoys me due to its ridiculous title. (Seriously, what kind of title is Precious:  Based on the Novel "Push" by Sapphire?)