This is rather petty but...
As an American, it pisses me off when Brits on the internet act like all Americans are so stupid and act like we did terrible things to other countries. While I certainly don't deny latter, bitch please. People didn't say "The sun never sets on the British empire" because it sounded cool. You guys literally colonized half the world. I've seen a lot of Brits trash America while acting like their shit doesn't stink which is hilarious, considering that a lot of the problems in America aren't totally alien in the U.K. Like obesity, islamphobia, racism and classism. The list goes on. Canadians and people from other nations can get rather smug as well, but they never get to the levels of holier than thou than some Brits get. I know every Brit isn't like this but to the ones that are, I have this to say to you: Shut the fuck up, britbong.
Also people who walk really slow in front of me. I walk like a New Yorker and I have places I need to be. Either walk faster or get out of my way.