People that feign helplessness when they don't want to do something for themselves.
People that drum on the desk.
People that think standard procedures don't apply to them. ('Oh I know we're meant to give reception notice if we have a visitor coming in but I thought it'd be fine if I didn't... can you do it for me?')
People that send a meeting invite, then roughly one million adjustment followups where they shift said meeting back and forth by half an hour or so each time. Just check everyone's calendar first and make sure you're booking it for a time that suits everyone!
Managers that think that if they say, 'I really want x done by y time' that makes it magically possible, even if there is no physical way that said thing can be done in that timeframe and the reason that it's suddenly urgent is because they didn't pull their finger out weeks ago and get things started while we still had a chance of hitting the deadline.
People that stop to have a chat right in front of the security barriers.
People that think I'm the office dogsbody because I'm the least senior. I have a very specific job and answer to one specific person. No, I can't 'just quickly tape up this parcel and book a courier' for you. I am busy doing the thing I was hired for. General administration is not in my job spec.