At work, having to queue for trivial things. I can accept queuing for lunch, but when it extends to queuing for the fourth time to go to the toilet, queuing to make a cup of tea in the kitchen area, queuing for the shower because some f**kwit is taking >20 minutes in there, queuing to wash up my cup, queuing to get a glass of water, queuing to sign in for lunch because someone can't decide what they want, I wonder if everyone is getting paid to p*ss me off.
Oh, and on the subject of queuing, I find it annoying when I have to queue for like 10+ minutes to do something that takes 20 seconds.