Things that annoy me at a "commercial" gym?... hmm. I am a powerlifter, so I go to two gyms, one commercial and the other a full powerlifting gym.
Half-squatters
People who curl in the squat rack
People who DO squat in the squat rack, then proceed to leave the bar fully loaded when they are done.
The guy who walks in and loads 225 on the bench only to quarter rep, bounce that shit. Then proceeds to walk off, leaving the bar loaded, of course.
Old men who flirt with young girls, also people who think the gym is a fucking club scene. GTFO.
Women who do provocative exercises, half-naked... Sure it's nice to see, but not while I am training! It's distracting, goddammit!
Large groups of fuckboys, that talk REALLY fucking loud to get attention.
The personal trainer who doesn't even lift, brah.
These people are NOT saluted, on a daily!