Another vote for 2D, primarily because 3D glasses make my eyes hurt.
It actually is the glasses, not the movies themselves. Even if I put the glasses on before the movie starts, I get the same pain in my eyes. It's a bearable pain, but irritating all the same. The odd part, I have perfect eyesight. I don't ear glasses and have never needed any medical attention for my eyes, yet 3D glasses cause me pain in my eyes. Worse part, my local theatre makes it more convenient to see 3D showings, so I pretty much have to suck it up.