1. Guys who lift too much with horrible form.
2. Guys who make hulk sounds or sound like steam is escaping with every rep.
3. Girls with way too much perfume on next to you on the cardio equipment.
4. +1 on the old naked dudes trolling the locker room, especially if they like to hang out and brush their teeth at the sink.
5. Guys who walk barefoot in the locker room.
6. Guys who sit bare-assed on the locker room benches.
7. Guys who walk up to the mirror and then angle away while they do a quick flex and check...yep, you're still skinny.
8. Guys who come up and ask me how much I bench.
9. Guys who act like more weight = tougher, because tricep pushdowns win fights.
10. Guys in spandex shorts.
11. ^ especially when they do crunches and look at you.
12. +1 on the squat rack being used for curls.
13. Guys who ask you how many more sets you have in the middle of a set.
14. Anybody who uses the gym as a meat market. Lift more, then go to a bar/club.