I saw Avatar this week at the Megastar Paragon in Saigon this week. I absolutely loved the move. Great visual effects, good story, great acting and animation--all around it really sucked me in and left me wanting to revisit the world of Pandora.
Be advised however that theaters in Saigon are playing some funny games with the movie. Some are falsely claiming sold-out screening, apparently to generate hype, but this is backfiring and actually discouraging people from going. When I went there were only a dozen people in the entire room, and other friend who've gone have said the same. Likewise, some theaters are falsely claiming to show the film in 3D, when in fact they are offering only normal screenings. Supposedly the only screens in 3D are at locations near the airport and in Cho Lon.
So, do go see the film in theaters while its here, but check with the theater before you go to make sure you are getting the screening you want.