I'll try to keep it as spoiler free as I can. Not that you won't be able to figure this movie out before all the characters are even introduced. 

James Cameron takes all the creativity that could have gone into developing a unique story in a fantastic setting and dumped it all into art direction and presentation. 

15 minutes into it (and I'm being generous here), the whole movie could have been figured out by anyone with an IQ slightly higher than a fork's. There are no surprises. Some scenes can be called foreshadowing but they're really not. They're just cliches. Cameron doesn't even try to disguise it.

Even in a children's film like Wall-E, Pixar gave kids enough credit by making the obvious villain something only most adults would be able to figure out right away had they seen 2001: A Space Odyssey. Did any one of you see the big red sensor in the captain's wheel and NOT think "oh ***, it's HAL" as soon as it started speaking? Didn't think so. 
BTW: if you really really like a girl that you've only just met for the first time, it's PERFECTLY okay to drag her unconscious body around, feel her up w/out permission and stow away in the trunk when her family takes her home. Cuz DATE RAPE AND STALKING IS CUTE! *** hate that movie... anyway, where was I? Oh, right.. Avatar.

The Navis (big blue dudes/Native Americans/Iraqis.. take your pick) come with built in USB devices in their hair that they use to jack into creatures to ride them or into plants to communicate with them. Thank you James Cameron, for clarifying that they have a close bond with nature. If they can jack into the forest and talk to it, how the hell is it such a surprise when the bad guys show up to a place it took them THREE MONTHS OF BULLDOZING ACROSS THE FOREST to reach?

There isn't a single creature in the movie that's not a derivative of something we already know. Wolves, horses, rhinos, dragons, etc. My favorites were a take on the shy plants, big red swirly red plants that shrink and shoot into the ground if touched and creatures that seemed like dragonflies that flew with glowing wings shaped like DaVinci's helicopter.

This is where, in my opinion, the movie shines. Art direction and presentation. The 3D elements were a nice touch but not overwhelming. In fact, I'd watch this movie again w/out 3D. There are no instances of the tacky overused 3D trick of something coming toward you off the screen where dumb ass audience members try to reach out and touch it. The 3D effects are a dressing, not the main course.

The overall design of the creatures, the plants, and even the native Navi of Pandora are done very well. It's a bit difficult for me to formulate my thoughts to describe this into words because I'm not very well versed in the intricacies of the English language. But here's my best try. 

James Cameron knew that he'd be using CGI to create these creatures, these alien people. They'd have to look different enough for the audience to be able to tell them apart by face. But they'd also have to look real enough for the viewers to be able to connect with them as if these tall blue creatures were people, not just animals.

A couple of days ago, because I have no life, I decided to watch the whole Matrix trilogy in one sitting. What I noticed is that I could totally believe that those mechs, ships and the sentinels were real. The people piloting the mechs, Neo and Smith during the scenes when they were rendered with CGI on the other hand were a different story. At the time of their release I thought they looked great but the scenes haven't aged well.

James Cameron had enough foresight to realize that if he's going to go for realism with CGI, it had better be in a way that doesn't allow the viewer to fall into the uncanny valley years from now when the technology is much superior and we've gotten desensitized to photorealism much like we have now since 2003 when the Matrix sequels came out. From where I sat, it appeared that he had succeeded. After 5 minutes or so of seeing the Navi on screen, I got used to them as if they were any other actor or actress on the screen. The only time anything looked out of place was when the Navi avatars wore human clothes. I couldn't help but think of this guy from space jam:


Avatar should be seen for the spectacular visuals and creativity that went behind them and nothing else. If you think you're going to get an original story, original dialogue or some kind of plot twist out of that movie, you will be sorely disappointed.

Did I miss anything?