Ok so finally seen it-- (sorry if you've heard this for the millionth time haven't read the other comments for spoilers............)
It is a nice movie, but still... there were many features in this film, key points, which will make it forgettable.
The story- we all now why... if we take Edward Scissorhands for example, we know it's an idea taken from Frankestein, but still there are many differences, plus you can't resist the charming of it- beautifully appealing for its simplicity. In Avatar I hardly cared for anyone, except for the girl (can't remember her name) and Grace. Even though I found the acting of the girl amazing (also loved her accent/voice), she just stood there snarling and smiling, because noone, from my POV, reacted to her in an original, appealing way. (Porbably all this CGI, constantly artificial visuals didn't help either) Everyone, except those two girls, felt empty as if I was eating a chocolate bar for the 1000th time in a day. I know I'm eating it, I know it's delicious, but I can't taste it, because I'm so fed up of the same bar over and over again.
The natural habits- this whole civilization with their traditions and everything, is very different to the man. Unlike us, they know how to keep contact with nature, they respect animals, etc. But when the true moment, the synchronization of Jake and the girl comes, they just kiss. (I even could see the same colours as the Lion King's "Can you feel the love tonight") Call me evil, but I was expecting something else in that and many other moments, with all that ingeniously designed nature.
The music- I think this is the most that let me down. WAY down. All tribal choruses stuck with super glue were very disturbing- not just because of their random moments, but the unoriginality. From time to time they reminded me when little Sid-girls are praising Sid in Ice Age 2. What's worse, the movie ended with the most common, vulgar female voice you can think of.
Extra stuff: Small butts on the avatars put me a bit on my nerves. Made me feel the body fell into pieces except the head.
This is more of personal thing, but I don't get why, to synchronize with animals, having a tail, they had to use their hair, the least part of the body we have contact with.
Didn't like the panther/wolves, many moments CGI looked like PSP and some other stuff, BUT all the avatar nature was so amazing that I didn't really care.
Actually, I think all the praise Cameron is receiving is due to all the people who created Pandora (yay I remembered a name) and nothing else.
P.S: I won't count the 3D because I don't know what it is like around the world, but my movie theater's dreadful. Only for time to time there were parts which looked like holograms, but that was about it. I paid 9? glasses for nothing.