Some of my Pet Peeves:
"My home course is better because..." Go and play your home course, in fact right now is a good time to start back...
Pulling up/down/out/destroying branches or plants because they're in the way. If you don't like your position, learn to throw better.
Loud music on the course. That's what earbuds are for.
Telling me repeatedly what a bad day you're having, when i know that you just stink up the course most of the time. (I'm actually bad for this, but I'm working on it.)
Or, complaining because you're not under par, when I'm 5 over.
Beer cans, bottles, pop bottles, wrappers, butts, etc.
Big groups, spraying throws, not lettin' me through. No, I don't usually ask, I'll just skip a few holes.
Talking while I'm throwing. It's my fault for not concentrating, but it's just rude.
Probably others, but most of these I just take without saying much. If you're not having fun, it's YOUR fault!