At the very least, see it in 3D.. we tried twice to see the IMAX version, but it was continuously sold out, so I wish I could comment on the difference, but can’t. :(
Saw it in 3D twice, it was really good and I really love this new evolution of 3D cinema – it’s not your old school kind where it’s kind of lame and basically it’s just random stuff coming out toward your face, it’s more subtle, like actually being in the scene. I think it’s pretty awesome. I don’t think it’s the best movie ever, but I personally really enjoyed the film.
Everything is better in IMAX, so I’m betting Avatar would be, too.