I watched Avatar yesterday with the Dolby 3D tech (in a cinema). For me, the most noticeable 3D effect is the HUDs in the control room. After a while, I forgot the movie was in 3D. The usual movie elements (story, character, effects, ...) were the main attraction. 3D didn't impress me as much, but it proved that the tech can be applied with zero fatigue.
The greatest annoyance is the weight of the glasses. It's uncomfortable at the beginning. I intend to watch the IMAX version when I am back in US. I was expecting a first-person, 90 degree dive down a cliff with full 3D effect, but it didn't come through strong enough (May be it's vomit inducing
).
This GAF thread has some info. Basically, look out for Acer, Samsung, Viewsonic and LG monitors (True 120Hz, HDMI 1.3 and above).