Gravity and Avatar stand out but as a general rule they don't do it for me. As soon as the camera moves quickly they seem to lose focus and be tricky to follow
These are the only 2 films I've seen in 3D and thought it was worth it. All the other films had it as a gimmick and it didn't add anything to it, in fact I would say some films are made worse by being in 3D.
Also, I wear glasses. So I have to wear TWO PAIRS of glasses at 3D screenings, making me look even more of a GONK than usual. So that's a personal gripe with 3D.
This is the most annoying thing for me too, they look ridiculous and aren't exactly comfortable after wearing them for 2 hours.