Here are some of the things which I find annoying and I would like to see what other travelers find annoying.
1. The PA system. The loud ding dong followed by an announcement, usually a final boarding call, then a final-final boarding call, then a more aggressive final-final boarding call.
2. Stiff officials. I mean in terms of attitude, not anything else. Impolite. Like, when you are going through the immigration process and someone wants to know what's in your hand luggage; I like to be asked politely. I don't like to be ordered to open my bag. When I am travelling through Scandinavia, there is no problem, everyone seems polite, but some officials elsewhere can ruin the first few days of a holiday.
3. Late passengers who sit next to me. If someone has been running from gate number 1 to gate 55 and arrive dripping in sweat, the attendants should show them to the bathroom and give them the courtesy freshen up kit. It's only a matter of time before they start to issue a fine to late passengers.
What things annoy you when travelling?