i got a term for people who do this, i call them a gym douche. heres my list and sadly one guy did all of them on it.
1. not reracking your weights when done. i believe if your big enough to lift it, your big enough to put it away
2. bringing a different work out buddy every time so you can talk about what you do, when you have been doing it for 3 months and look exactly the same
3. not putting any noticable resistance on a machine, and just staring off into space zoned out as you do 10 reps like its doing more for you then when you get the diet soda from the fridge
4. sitting on a piece/ putting foot on it/hovering over a piece of equipment, talking to workout buddy, having someone else come up and ask to use it when your not and saying,"im almost done." and using it 15 minutes later
5. grunting loudly, i can understand a small urr from exhaling, but not one where i can hear you outside the gym.
6. using the cell on equipment. stand up and out of the way or go outside to talk
7.not wiping down stuff
8.using one piece of equipment/weights but doing so in a way to block other pieces of equipment.
9.when i am bouncing between 2 machines( for some exercises of larger muscles i'll do a set on one, rotate to the other, then back to it, saves time and keeps my heart rate up, so my time is halved between two different exercises) and someone slides in without asking, and does number 3 but does it for 20 minutes. then stops and stares off for 20 minutes, and does it again
10.using a piece of equip, resting on it for 10 minutes, using it again for 2 reps, rest again for 10 minutes x infinite to the point where i am now waiting another hour doing filler exercises to finish off my plan for the day