My favorite part has got to be when Jake wakes up in his avatar body. Putting myself in his shoes... a paraplegic... never being able to walk again, then waking up to feel your legs, walk, run, feeling the sand between your toes. Knowing how emotional thinking about what that must be like makes me, I can imagine how people with disabilities must feel.
Personally I find the move awe inspiring. The discipline that Cameron has, in this and all his movies. So much of movies now is so cheap... just for profit... but the backstory behind the movie such as how he waited about 10 years to make it just so technology could develop to where his vision could be realized, plus the way Cameron is unrelenting in his pursuit of perfection... even when a movie made this way is not perfect, you have to respect the discipline.