A few things that annoys me in the gym:
1. Being freakin' loud in the gym, whether you're lifting or not. If you're lifting and screaming as if someone stepped on your balls all the time, perhaps you should lighten your weight or face an injury that will really FEEL as if someone stepped on your balls!
2. Hogging the machine/weights with a bunch of friends and spending like 10-15 mins between each bloody set chatting! C'mon lah, go to the gym, do yer shit and get out! Wanna chat, do it after you're done or go mamak lah!
3. The only guy previously in my gym who keeps taking off his shirt and pulling up his pants until they resembled boxers, then uses the weights and keeps making sex noises. We all KNOW you're nice and ripped, but no one likes a bloody show-off. Furthermore, he's pissing off the ladies coz they think he's being indecent! (I know this is a isolated case, but just wanted to point it out =P)
4. People who leave a puddle of sweat on whatever machine/equipment they use and don't both to wipe up.
Now what about you? What ticks you off at the gym?