I have never been so close to leave the movie theater, as i was when seeing Avatar. Sure, it's very beautiful to look at, but, if you've seen the trailer, then you've seen the movie! It's basically every movie clichés put together in one horrible and so unoriginal movie. it's a mix of the "last samurai" meets "Pocahontas" meets "Atlantis"! it's by far the most horrible storyline since Ed Woods' "plan 9 from outer space".
Not once are you surprised by the turn of events in this movie, and there's so many bad movie clichés in it, and so many things that just doesn't make any sense at all (even in their universe). for example, the last fight scene with the giant robot and the Avatar. It really doesn't make any sense at all, that the robot is carrying a 8-foot-1 hunting knife, just in case he loses his gun (which could easily have been attach to the robot!), and that the robot tells the avatar, what he's about to do, instead of just doing it (A good example of a bad cliché).
If you want to see this movie, i recommend you either see the trailer ( as that is enough for you, to litterily, call every scene in the movie) or you go out and buy Atlantis and just Imagine it with smurfs instead of underwater people.