Hayao Miyazaki's Naussica - In the Valley of The Wind is an absolute favorite of mine, a sci-fi ecology drama stunningly realized. James Cameron's clearly a fan, too, because he's stolen from it wholesale; then he added floating mountains stolen from Laputa - Castle in the Sky. Despite all that thievery, the film's still shockingly predictable.
Dances With Wolves gets borrowed, too. Wholesale.
But it is the work of fantasy titan Jack Vance that Avatar draws from most blatantly; his Son of the Tree, in particular, suffers the greatest act of pillage. Works such as The Dragon Masters, Big Planet, and Planet of Adventure quadrilogy provide rich source material also.

Despite all these rich influences, the result is fairly bland stew.Yes, the visual effects are striking, but the whole shebang made me nostalgic for the time when special effects would serve the story. The "game changer" (fuck!, I hate that expression) here is that a flimsy waif of a story is now serving the special effects. Is that really progress?
Is it reasonable to expect an amazing script from a $300 million movie? I think so. Do you?
Final nail in the coffin is the casting of the charisma-free Sam Worthington. I didn't like him in the Aussie Macbeth and I didn't like him here one bit. Also, his wavering between an Aussie and American accent distracted me unnecessarily.
I mentally slogged through this because every plot turn is excruciatingly predictable; I just sat and waited for the inevitable to come and go.
What I did I like? Zoe Saldana as the blue-skinned heroine 'Neytiri'; she's terribly sensual.
While examining the features of the film's native population, the Navi, it occurred to me that these folks all have noses like 'The Tenia' (Jo Prestia) from Gasper Noe's Irreversible. They just don't possess his savagery.
