Most things that annoy me are in general considered annoying I think: being cut off mid sentence, being talked down to, insulted or ignored, advertising (thank god that industry is dying), people being willfully ignorant on a topic they know nothing about, hypocrisy, etc...
There are some things that annoy me more than they should and don't annoy most people though.
One is certain smells tend to set me off, like the smell of boiled eggs, kim chi, and certain other strong smelling foods.
Another is a lot of tags on clothing, especially if they tend to stick straight out and scratch around on my neck.
A third is political correctness since it's been used so often these days to attack many of my favorite things, like gaming and heavy metal.
Also I despise pop music, not as in popular but as in what we call "pop" today, like Britney Spears, Miley Cyrus, etc..
I also tend to get upset over the complete disregard for source material by movies and shows based on books, comics and manga.