The extended version was a lot more fun and included scenes vital to the movie and its impact which drove me to change the rating from a 9 to a 10. I hope the production studios do not make the mistake again by dictating Cameron the run time. He already does his job perfectly, so leave him do what he does and don't ruin the movie by cutting on the run time.
Let's look at the world of Avatar. It's a moon of a planet in another galaxy that seems to bring our fantasies to life with foreign lifeforms beyond our imaginations - monkeys with four arms, crossbreed lifeforms that seem to combine horses with zebras, giant flying creatures that we could probably only compare to pterodactyls, and the list goes on. The plants in this universe are strange and beautiful in their own way as well. Everything on the moon seems to have a blue or green tint to it, practically force-feeding the audience the idea that this world is supposed to represent a sort of Eden. The most notable factor of this world is the human-like creatures labeled as the Na'vi can literally connect with many of the animals as well as their sacred tree through a link that ironically resembles the way digital technologies connect in this day and age. Such a world and the connection between the natives and nature preach heavily for environmentalist movements. Finally, we have to remember this world was created with digital rendering, and the world is nothing short of beautiful.
Disregarding the elaborate world-building involved in this film, the movie is filled with cliches, cheesy dialogue, and one-dimensional characters. Let's look at various ridiculous aspects of Avatar. The name of the mineral the United States businessman (played by Ribisi) is looking for is Unobtainium. Surprisingly, that is not a joke. The head of the military sanction is a one-dimensional character set out only on destroying the Na'vi since they're "savages" (according to his cheesy monologue at the start of the movie) and so that his superiors can get their hands on the Unobtainium. He trusts Sully and believes he will report to him since he used to be a marine and makes a promise to get him his real legs back - that is before his use of the Avatar allows him to enjoy running again. Dialogue coming from this character as well as from Sully and even Sigourney Weaver's character are laughable at moments, making us ask why Cameron didn't consult many co-writers.
What this movie lacks for in quality of writing, however, it makes up with heart. The ideals the Na'vi strive for seem like they have been forgotten in the real world today, and they are what draw us and Sully to them as a community. We cheer for Sully and the Na'vi in the climactic battle within the film which lives up to other great action sequences in recent years even if most of it is CGI, though this film requires heavy use of CGI throughout, so why would the action be any different?
Avatar is good; it cannot be labeled terrible simply because it takes plot points from Dances With Wolves, but it does lack quality based on its disregard for good dialogue and some underdeveloped characters.