People who target one person and try to make them feel like trash for no apparent reason, it's even worse when they get their little gang of idiots to do their bidding for them.
I'm talking from personal experience here, did I kill someone they love or something because I don't see how what they say and do is justifiable. I do nothing to these people that I know of, they never have the guts to actually express how they feel politely. Cowards, bullies and idiots the lot of them.
These people just lose every ounce of sympathy from me, if they ever find themselves in a situation like that then I hope they feel like utter trash, however I would never participate in it nor would I help them as it should be an eye opener for them.
I also dislike when people chew with their mouths open, it's impolite and when they cough/sneeze around me too; it's gross.
I hate when people are overly boisterous, it's very irritating to be around people who never shut up because I like to be in quite environments hence why I have no loud friends.
Unsophisticated people are also hard for me to be around, I can't put up with idiots as I don't like answering questions every few seconds.