I've seen Avatar twice now. I already reviewed it on my personal blog. I didn't love it exactly, but I had to see it a second time because, despite its flaws, I knew my seven year old would think it was awesome. He did.
However, I do want to add one quick thing about it. In the past, I've complained often about the way movies portray scientists as closed minded eggheads who don't understand the way the world really works, and skeptics are regarded as blind fools who wouldn't recognize evidence that's whacking them over the head with a cricket bat. For more of this discussion, see the Atheist Experience archive, episode #530 about "Skeptical straw men in fiction."
One thing that Avatar really has going for it is that the scientist characters were clearly right. The military wanted to charge in with guns blazing; the scientists just wanted to study the planet's ecosystem and establish diplomatic relations. The scientists emphatically were not egotists filled with hubris who were tampering with forces of nature they did not understand. And when they talked nerd talk, it's presented as charming. They got geeked out and excited about the stuff they were seeing, and this was treated with affection for new discoveries. When Grace visits a new part of the world in order to try to treat her serious wounds, the first thing she says is "I have to take some samples!"
So the movie itself was thoroughly implausible all the way through, and the political aspects were annoyingly oversimplified. But treating scientists as real good guys and giving them believable reactions counts for something in my book.