Let me think, am I allowed to name more than one? This is going to be one heck of a list!
My pet peeves are the following:
ABC gum, chewing with your mouth open, not rinsing dishes, one single thing out of place in an otherwise clean area, crooked picture frames, dirt under finger nails, dirty face, chat speak, all caps speak, when people text while I am talking to them, when people leave without saying goodbye (not strangers or anything though), when people act like the are listening, but really aren't, when people hurt each other on purpose, when people kill bugs/insects just for the heck of it, when people allow their pet to use another's property as a toilet, when people say to me "I have never heard you talk before.", when annoying people get all the attention, sprinklers that water the street or sidewalk, people turning the TV off when I just leave for a second, empty boxes left in the pantry or fridge, constant use of slang, slurping anything, when people spoil surprises, when people expect you to do something without them ever asking you, scratched cds, broken clocks that are still mounted, wide ruled paper, itchy tags, when people think they are all that, when people are obsessed with a famous person, people who are obsessed with twilight, people who won't stop trying to get me to read twilight, the fact that actors/actresses get paid more than teachers, when people say there is no such thing as a 2 dollar bill (and refuse to be proven wrong), people that argue way past when the discussion ended, people that try to get as many friends as possible (even though they don't know them) on facebook/myspace just to look cool, people who never shut up, people who ignore me, people who think they know everything, spitting into/onto anything but the bathroom sink, people who pee in a pool, people who wear shorts that don't cover their butt, people who eat in front of you when they know you are hungry, the toliet seat left up, poeple looking through my phone without permission, people who assume, people you genrelize, clicks, bratz, copy cats, the annoying dog next door, when people mispronounce my last name many times, when people don't believe me, falsly accusing people, people who cuss at least once in every sentence, people who shut the door in my face, people who don't think I am old enough to buy pencils myself (stupid staples employees, I'm 15!), people who stare, people who point at others, meusems that have birthday parties, people who say "like" every like 5 seconds like that is like annoying, bullying, when people forget to lock the doors at night, when people wear their hats backward, scemo "music", rap, when people listen in on my conversation, when people talk about me like I'm not there, people who make fun of me because I don't eat red meat, people who make fun of my family, people who skip in line, crinkled paper, when people wear all of one color ( when the colors are different shades), the fact that my spelling is horrible.
I love answering this question, I could go on for days.