I just dislike conversation-killing people. I'm not particularly talkative, and I prefer to only talk if I have a view to express, a fact I think is interesting, etc. But people who just interrupt, CONSTANTLY talk - giving no one any space to reply, and if they do attempt to, the person just carries on talking but LOUDER; made worse if they are just repeating themselves arbitarily - change to subject when you had something interesting you wanted to say on the last. I hate it when I mess up my words, which I do often (I am a poor speaker. I mess up all the time and say "like" and "um" because I panic) and no one will just let it go. Okay, it can be funny, but after a little giggle, can you please let me continue?
Leaving the door open. Made worse if when I call after them "Please close the door!" they ***** at me about being "too lazy to do it myself".... but you barged in on me, left the door wide open when you could have EASILY shut it as you were standing RIGHT NEXT TO IT after leaving, so why didn't you? You know I like it closed! This has lead me to automatically saying "Close the door" as people head towards it... now I get bitched at for being "rude" because they think I am trying to get them to leave. Arrrgghhhhh!!!!
People complain about me being a picky eater. I don't decide that disliking my food is fun, you know. I HATE not liking food, and having like 2 things on any menu that doesn't repulse me. I'm not going to eat food if I hate it, and if that offends you, I'm sorry, but I cannot stand eating disgusting food.
I have so many things like this, but I am sure my rambling is on someone else's pet peeve list, so I'll just shut up now.
EDIT: Oh, another daily pet peeve I just need to add. Judgemental people. People often lean over to me and go "ugh, look at that woman's dress!" or "her skirt is so short, what a slut" or "that guy is so fat". Seriously, do you have to find flaw in random people you see? Just leave them be. I don't even notice if a woman has an ugly dress, or a short skirt, or is fat. I usually just go "mmhmm" and leave it at that. It bugs me that people just care so much about superficial things.