Ok, I voted for the people who scream at everything even if it's not scary. I understand when people scream because they are scared and i actually enjoy watching people who scream when they are scared. It's the people who just walk around just screaming that really gets me.
Another one of mine is people who point out every single scareactor. It ruins the experience for someone who hasn't been in the house before.
My last one is people who wont go in the houses. Me and a couple of friends went to HHN last year and one of my friends brought his girlfriend, which was ok with everybody, but she wouldn't go in any houses and my friend only got to go through 2 houses. I understand being nervous going into a haunted house, but if you pay the admission to get in then why wouldn't you go in them.