Jason and the Argonauts and all those Harry Hausen movies had personality in bucket loads, even today they stand up for what they are, perfect .. no, but damn good stuff, Avatar lacked personality, it lacked anything to love about it if you see what i mean.
BTW - in our house the name Avatar refers to the cartoon "The last air bender" which we all loved and still do, so their use of the Avatar name has annoyed and confused my kids

anyway .. plot .. corporation inhabits planet and want to drain of natural resources, inhabitants would like to live in peace and MAD American General type character just want to blow em up to get the job sorted - stretch that out for 3+ hours and there is your movie - anyway, like the Transformers films its not about plot at all, in fact plot would seem somewhat of an inconvenience to these filmmakers - its about creating an experience, this time splattered with 3D and more animation than you can throw a stick at
3D is annoying the hell out of me, we know why 3D keeps coming back .. to get bums on cinema seats, with so many now having BluRay and massive home cinema systems, and of course people downloading movies has kept the cinemas a little low on turnout - so now we have to suffer a mass of 3D films that actually cost more to see - not impressed at all