No wonder Cameron hadn't directed a feature-length movie for 12 years; obviously, creating Avatar mandated such time. Touches of Aliens and Dances with Wolves are scattered throughout, but for a true allegory, I believe Avatar is Star Wars for the new generation. The superb mix of fantasy, spiritual, philosophical, and political themes raises the story beyond any sci-fi concept seen in decades, and the additional message for humans to blend with their green environment is one to cherish. After 160 minutes, I did not want this visually stunning masterpiece to end, because I had seen my top movie of 2009.
(Disclaimer: Although Cameron had planned this mainly to be watched in 3-D, I chose to watch the 2-D screening, just because I wasn't sure I could tolerate more than 2 hours of 3-D without getting a headache. Maybe I'll try 3-D on the second round.)