Arsenal. The whole thing is just so boring and they're completely unavoidable.
Bantering social media twats.
People who only know football players from FIFA and never actually watch anything other than a handful of Prem clubs.
Any animosity between fans outside of the ground. Take the piss and tease each other (within reason) during the game and then just go home or have a beer or something. I hate seeing the ringed in away fans outside the ground as people stream past puffing their chests out and pointing.
"Your Liverpools, your Evertons, your Watfords....."
Players making gestures and gang sign type things when they score.
Dele ****ing Alli.
The media's obsession with managers.