I really liked Avatar, in a kind of - "if we are going to have blockbuster movies, I'd rather they be like this" kind of way. Something like Eternal Sunshine of the Spotless Mind, or I Heart Huckabees, or Memento or (insert your favourite thoughtful movie here) will always impress me more than a blockbuster like Avatar, but its still a very fine film and I'm impressed by Cameron's talents, which stretch from the very technical side right the way across to the artistic realm.
Everyone pretty much agrees that the visuals are amazing. Plot and story
wise: although I knew quite a lot about this movie from watching the
trailers and reading the various leaks over the last six months, and I
pretty much knew how the story was going to play out (I mean, you can
figure that out from the trailer) there were still lots of parts that
made me think 'oh, thats a neat way of doing that'.
Something that hasn't got many mentions so far:
I knew this was a film where the humans were the invaders and the bad guys, but it took that concept to quite an extreme. The line near the end of the movie: "The Aliens were sent back home to their dying planet" ... think about that line and the implications ... the movie doesnt really spell it out, but it hints earlier on that Earth is in deep shit and Unobtainium is so valuable because its helping to solve that problem, or work around the problem. Avatar ends with Jake leaving his human body behind, and a couple of his scientist friends staying with the Na'vi. The rest of the humans are sent back to their wrecked planet, where presumably they will die as a species unless they find another planet like Pandora to exploit, or come back and try to take Pandora again. This film's happy ending is basically hinting at the end of the human race. Thats pretty radical for a blockbuster that millions of people will see.
I thought this film would be more like the humans and the na'vi coming to an understanding, learning how to co-exist in the universe, or something. But thats not how it ends.
Think about other big sci-fi films/franchises: Independence Day - humans win there, by being human. Sure, there are some bad humans in that film, but overall humanity wins through. Or, say, Transformers - the giant robots find some useful and spirited allies in some of the humans, and they fight on together. Star Trek - humans rock, in those stories. Doctor Who - the doctor admires the human spirit, and is generally very interested in protecting them.
Granted, the idea that humans suck as a species is not particularly original in Sci-fi, but its pretty unusual in big-budget blockbuster seen-by-millions Sci-Fi.
In the final confrontation with Quaritch, when he says "How does it feel to be a traitor to your race, Sully?", Quaritch is literally right. Its not just that he sees things differently from Jake, a political disagreement about the best way forward for the human race. It is literally true - Jake's actions, in getting the planet to unite against the humans, may well lead to the destruction of his (former) race.
Also, artistically, there's something obvious but powerful going on in parallel with this message - as a viewer you naturally identify more and more with Jake and the Na'vi, and enjoy the Pandora scenes much more than the grey, dull human scenes in the base. So at the end when you see your race being packed off home to oblivion, you totally go with it.
A lot of reviews have said that the movie has an environmental message - and thats true, but its sortof more than that. Its like a meta-environmental message: that humans are fatally flawed, will most likely mess up this planet, and then if the universe is really unlucky, they'll make it into space and start messing up other places too. Avatar, like Bill Hicks, views humans as basically 'A virus with shoes'.
I could go on about that for a while (like, is Cameron just choosing such a message because its topical, or has all his underwater nature study made him really believe that?). In a time when we real humans are struggling to make an agreement to (rightly or wrongly) limit Co2 emissions, which is a short step along a road we have to face someday - that is, learning how to live as a race on a planet with limited resources - and in a week where we failed quite badly to even make short steps along that path, this aspect of the film really affected me.
(originally a comment in this metafilter thread)