The most annoying thing for me in terms of pinball etiquette is people hovering over the game while you play. I was at a tournament recently where one of the participants, a 13 year old girl, sat a stool next to the game, almost leaned over over it, and literally mocked you when you drained. None of us wanted to say anything because we were from out of town and her father was running the tournament. There were others that stood very close too. It was a smaller place, but there was still enough room to give a player some room to breathe. This may be okay if you're hanging out and playing with your buddies, but certainly not a tournament setting.

I've also had instances where I'll be playing on location and a kid will come up and literally hang on to the glass to watch me play. I'm always hesitant to say anything because I'm just practicing and in a way it helps promote the future of pinball, but it's terribly annoying.