Every aspect of the movie is brilliantly realized. You can easily tell that there's so much more to this world than we just saw in this movie.
The CGI was so amazing that at any point I didn't go, well that's fake. The way the Na'vi are animated is completely amazing. Watch the eyes of the characters. The 3D makes this a very immersive movie and at no point it's gimmicky.
The emotional arc of this movie is one it's strongest points. We go from rooting for humans to rooting for the Na'vi without even realizing it. Very well acted, I hope that Zoe Saldana will be nominated for a supporting Oscar.