People that put BNIB on the sales thread and then right after put only test fired or plinked or ranged or only games it once or only a few scratches from mounting a scope or feeding a mag.
People that are so lazy (not cheating, lazy) to walk back to spawn so they walk 10' into the bush and spawn back in.
Game organizers that are not organized!
People who run up to you point their barrel in your face and ask why they can't run their bolt action without taking the course first.
The line "camelbak's are stupid and heavy, damn I'm thirsty"
This is more of a love then a hate item but nothing is worse (better) than the group that shows up with their brand new never fired shiny clear soft gun that they were so proud of and the look on their face when they see what everyone else has.
The 90lb saw gunner, my favorite line from gone in 60 seconds comes to mind. "Hunny you can't drive, I can't swim, i know i cant, so you know what I do I stay my black ass outa the pool" lol.
The whack a mole player... They pop up, You hit them, they pop down, they pop up, you hit them, they pop down. always a classic and why I started running cameras with zoom.
Blatantly stupid friendly fire... Example, the entire tan team running towards you with the Green teams flag obviously you open up on them with the saw gun, kill every last of them them, stand up and cheer and high five the guy your with... It still has not sink in o wait I'm also wearing tan, did I just screw up? (True story)
Saved my favorite for last, the guy who shows up late and boxes other vehicles in because there was no close parking left.