My pet peeve is slow play.
In particular my biggest pet peeve by far is the mixed group.....often oldsters.....who insists on playing split tees even though the men in the group absolutely suck.
Lets face it there are alot of elderly people playing the game, more power to them, but if you can't advance the ball a reasonable distance (forward, not sideways) you have no business playing the middle or back tees while the lady's in your group play the fronts. Play from the fronts guys and speed it up.....better yet let people play thru and cut the attitude when people ask to play thru.