I gave it a 9/10 too because the visuals were spectacular. For plot commentary... click on spoiler button. It's really hard to commentate without ruining the plot for those who haven't seen it. People are not exaggerating when they say the visuals are amazing.
The plot is basically like an adult version of Pocahontas. You've got humans, who are the British of Pocahontas, coming to Pandora to find unobtainium, a highly profitable resource. The Na'vi, what Loveless calls "elongated smurfs," are indigenous sentient beings living in tribes, similar to the Native Americans. Then, of course one of the humans falls in love with the chief's daughter, and the plot escalates from there, where Jake Sully must choose between his own people or the Na'vi, just like John Smith needed to choose between the British and the Native Americans.