The special effects were spectacular, although the 3D didn't really add anything for me. It would have been just as breathtaking in a 2D IMAX format.
Storyline was predictable but well told. The characters were generally 2 dimensional, but the actors did a fantastic job with what they were given. The development behind the Na'vi culture and the world of Pandora was well thought out.
Cameron didn't pull punches when it comes to the atrocities of war. It portrayed both the honor and the horror, the futility as well as the necessity.