Space hogs, grunters, late-comers: Who or what bugs you most at the gym?

"Has 'Portlandia' done a skit on middle-aged, passive-aggressive yoga types? They save spots for their friends and glare at you if you encroach on their blanket space."

http://www.oregonlive.com/health/index.ssf/2014/01/space_hogs_grunters_late-comer.html