This is the opposite of what this thread is probably looking for, but it's probably a worst experience for somebody.
I was either in university or recently graduated, and saw a movie with a group of friends. I think it was Cruel Intentions, but I also can't recall why I'd go to that, so not sure.
There was a large group of high school kids in the row ahead of us. Mixed group of boys and girls, and the boys were directly in front of me. They were very talkative, so early int the film, I thought I'd politely, but firmly, ask them to not speak during the film. I probably wasn't as polite as I thought, and they shut up pretty quickly. Every once in a while, one would start talking, and the girls they were with yelled at them in shushed tones, saying that "that guy" (me) was going to get mad again.
I don't recall a thing about the movie, but enjoyed the power that my one comment seemed to have.