I rather enjoy the community aspect of going to the movies. The Rocky Horror Picture Show absolutely must be seen in a theater. The experience is highly dependent on the crowd. I was lucky and saw it at the midnight matinee at my college campus theater. It was a real eye-opener.
My girlfriend and I saw Do the Right Thing in a suburb of Boston and I swear we were the only white people in the theater. As the tension heated up on screen, I thought "we're not getting out of here alive." Of course, nothing happened. Nobody paid us any attention. But I learned something about myself that I wouldn't have watching it at home.
I saw this Pink Floyd concert movie in a local mall and there were maybe eight other people in the theater, all of them smoking pot. It was a very mellow afternoon.
I can't say I've ever had a bad experience in a theater. Of course, if you go see a G rated movie there's going to be kids running around going crazy. But what did you expect?