1.) The Rack Addict. This is the guy who picks up a pair of dumbells and stands so close to the rack he's almost touching it -- inevitably right in front of the weights I need. If he could back off a couple inches I could get them, but either because he's worried he's not going to be able to handle those 30-pounders or -- more likely -- he can't bear to be that far away from his reflected biceps in the mirror, he won't back off.
2.) The Moaner. I will defend to the death -- well, maybe not to the death, but to the bruising anyway -- your right to grunt when you work out. (I refused to even consider a gym in my area that outlaws grunting.) But that's an involuntary reaction to exertion and as such, understandable, but not the guy who picks up a weight and immediately starts moaning like he's auditioning for a porno. What is wrong with your wiring? If lifting weights gets you off that much, you really need to invest in a home gym.