For a while at work, I was getting annoyed with people getting their garbage near the garbage cans, but not in it.
Ooh, I have to bust myself. My wife's pet peeve - well, one of them - about me is that I'll put dirty dishes in the sink, but not the dishwasher. I've tried to correct that and check if the dishwasher is ready to receive dirties. If so, into the dishwasher they go, and all is well. If not, then into the sink. I think the next pet peeve will be not emptying the dishwasher. I'm sure it'll be something.