Finally, a list I will be able to finish with zero trouble...
People who waste my time. As a busy woman I don't have time to waste. So the checker at Smith's who stopped my checkout process to sniff my dryer sheets and then launch a conversation about them before continuing was not my favorite person that day. People who walk slow in front of me, meandering, when I can't get around them. People who drive the speed limit limiting my ability to go as fast as I wish. (Yes, I am a speed demon, why do you ask?) People in the express checkout lane in front of me with more than 15 items. People who stop in the aisles at the grocery store to talk to someone else and block the entire aisle. Meetings where nothing gets accomplished. Yes, this category has many, many sub-categories of which I could go on and on.
Having to pick up after Big Sister. This one sucks and is more than likely my own fault. For eight years of her life I had enough time to baby her and go behind her whirlwind cleaning up after her since, after all, it was just her. Now that we have added Baby Sister, I don't have the time or the energy. It might kill me before she gets the hang of picking up after herself.
Baseball. I hate everything about the sport and the fact that they play it practically all year is SO annoying. And, no, this does not make me un-American. I am allowed to have this opinion.
People who don't pull their weight at work. This is a huge one - people who wander the cubicle halls and chat all day - either in adjoining cubicles within earshot or at intersections that I have to walk past. They annoy me even if I don't know who they are.