James Cameron's science-fiction epic has a very simple story which is more than made up for with some spectacular visuals. The premise is that paralyzed soldier Jake Sully (Sam Worthington) volunteers to go to the jungle planet Pandora to get enough money to get his legs back. His identical twin brother, who had trained for the Avatar program, was killed and he's the only one who can operate the body since it was made with his DNA (and identical twins have the same DNA). He's the only soldier in the program and all the others, including head honcho Grace (Sigourney Weaver) are scientists. The Avatars look exactly like the native humanoid species, the Na'vi. They are seven feet tall, cat-like, blue and have tails. They are also tuned into the planet's consciousness via neural interlinks to both animals and plants.
The humans, who are there working for an evil corporation, are mining a rare metal that is only found on the planet. The biggest deposit is right underneath the natives' home, a gigantic tree. Jake's mission is to learn everything he can about the natives and ultimately convince them to relocate. However, in the next three months he ends up falling in love with Neytiri (Zoe Saldana of STAR TREK) and has to decide if he's on the human's side or the Na'vis' side.
The 3D is effectively integrated into the story and doesn't draw attention to itself with crap flying out of the screen. As I said, the story is exactly what you think it will be, and many of the actors are typecast, with Michelle Rodriguez as a tough soldier, Giovanni Ribisi as a slimy, sociopathic businessman and Joel Moore (BONES) as a nerdy scientist. As I was watching the movie I kept on thinking it is like an expanded, overblown version of Ursula K. LeGuin's book, THE WORD FOR WORLD IS FOREST.
The computer generated effects are, of course, amazing. AVATAR is not James Cameron's best but it is a damn good adventure movie.