I don’t have much to add to the other glowing reviews out there. Avatar a movie worth seeing, in 3D, on the big screen, because it changes your expectations of movies in general. The story is classic, maybe cliche, and the acting is fine, but it’s all about the effects, the world, the blending of computer-generated and real life. Amazing. Go see it.
I think my friend and colleague Kyle just about nailed it in his review, which has more details: Why Avatar Will Change the Way We Go To the Movies.