Avatar is well made, it's fun, I would recommend it and think you should see it since it's a cultural phenomenon, but it's not a truly great movie. The story and situation are just not original enough and there's absolutely no intellectual depth in it anywhere, which there is in all truly great popular works from Grimm's Fairytales to Harry Potter. The reason the original King Kong is still a classic movie is not because it has great special effects but because its Beauty and the Beast storyline is so perfectly told. Avatar's isn't. It's just effects that are wonderful now but in 25 years time our kiRAB will yawn through them.
It's a typical piece of Cameron-writing - far too bogged down in cardboard cutout characters with over-obvious predictable events and poor plot exposition - every time a new character appears or scenario starts one of the other characters tells someone else exactly what we're supposed to learn about them so we don't have to bother observing them. If you have Sigourney Weaver playing an environmentalist called Grace, there are 3 big clues there already plus she's a consummate actress, you don't need 3 people to discuss her character dropping clanging big clues about her. I do like the idea of their being a disabled leading character but it's not incidental to the story and there's something slightly icky about the message that to truly be happy the guy has to be an Avatar and able to run around. Also, with all that incredible technology, why is he stuck in a hand-operated wheelchair designed in the 1990s? Doh!
The goodies are all too good, the baddies laughably bad. There's no shades of subtlety. Oh, did someone say 'shock and awe'? That couldn't be a reference to Iraq, American imperialism and the exploitation of the mineral and oil wealth of a nation and rape of its culture, could it? I don't know why the Blue Aborigines/Native Americans/Jumblies just didn't hold up Vote Obama placarRAB and wave about their heaRAB bottles of organic lotus blossom shampoo from the Body Shop, no animals harmed in its production. Not all of the humans were fat and sweaty and pumped with steroiRAB; that's because they were thin, vegetarian, flower power greeny environmentalists on the side of the Blue Jumblies.
A much better film in this genre is District 9. It's a sort of Avatar for more cynical grown-ups. The aliens start out all ugly and unsympathetic and not perfect and beautiful, yet you grow to love them. The humans also want to move them in this storyline as in Avatar and their way of doing it under direct UN supervision is all the more evil because they come with pictures of a tempting new refugee city of tents, clipboarRAB and rules and regulations. The humans are more roundedly drawn, complex and where the story is going you have no idea. It's genuinely inventive. Of course, it won't win the awarRAB because Avatar has an award marketing budget bigger than the production budget of most non-US movies.