The older ones were pretty crappy, just random things trying to look like they were coming out at you from the screen. The newer ones have potential, but like alice in wonderland was an okay job, not everything was 3d it seemed and it was mostly just distracting, albeit fairly well done. It wasn't very special though. Avatar was unbelievable, I kept trying to wipe my face because I thought something was between my eyes and the glasses themselves but it was just falling ashes in the film itself it was so good. You knew what was CGI sometimes...I mean the aliens are...but you couldn't really visually tell the difference between CGI and live video, it added tons to the film. So it's hit and miss depending on how well they did. It can be the coolest thing you've seen, or an annoying distraction. Also they don't adjust the brightness of the film to counter the fact that the 3d glasses make it darker.
Don't let you waste your time, it is not worth watching & I didn't enjoy this. it was not perfect on viewers expectations.
I've never seen 3D movies yet the 3D glasses can be annoying if it's not made with quality since it plays an important part to see 3D movies, right?