This topic rules.
1. The guys that sound like they're blowing a blast of steam out of their mouths every rep. SSSTT SSTT
2. Guys that yell for no reason, when doing light weight. I understand that you need motivation for the heavier stuff, but come on. 225 on the bench and you're yelling YAAAARGH?
3. The shadow boxers mentioned earlier. And (not racist, just pointing out an observation) they are always black.
4. The guys that just stand around watching everyone, taking 20 minutes on a set of one particular exercise. You've all seen em. They just sit on the machine and watch other people work out.
5. Mentioned before, the random guy that comes up to watch you do a heavy set, then shakes his head after you're done, and says a random (albeit positive) comment.
6. PHANTOM SPOTTER
7. The guys working out next to you talking about how they'll never touch creatine, man. I don't do that steroid stuff.
8. The guys that stare at you when you mix some Cellmass after a workout, then talk to each other about what that stuff could have possibly been.