Stinky guy, we can all smell the difference between sweat and BO!
"That's a lot of weight" guy, annoys me. More annoying because I don't lift what is considered heavy weight by any standard.
1/4 squat guy. Even more when he asks for a spot.
ILS guy
Chatty guy/girl. Unless the girl is hot, then she's allowed to talk to me twice an hour.
Teenagers who come to hang out, not work out. They end up slowing everyone down.