This movie will rock your eyeballs; showing them something they never knew they wanted to see so badly.
James Cameron shouldn't brag too much about the "original plot" - it's basically "Dances With Wolves" in outerspace. White man incorporated into a foreign culture. But it takes place in a futuristic spaceworld, so get ready for unexplained technology leading to large plot holes.
But if you can ignore that and let your eyes (not brain) do the work, it's an aesthetic dream. I completely forgot that I was watching a computer do all the work - it felt like Pandora and the Na'vi were real.
I highly recommend you see this in the theatre in 3D. It's hard to be disappointed.