When I'm having a conversation and some random jackass thinks they have to comment on specific things I've said because they feel "offended". I don't care about you/your race/your disabilities/etc. I speak how i speak, act how I act, and am how I am. I'm not just gonna change because someone tells me they disagree with something, it's just going to get you hit.
People that refuse to see both sides of an argument and side with one side adamantly due to their own prejudices/biases. I'm not religious, but a lot of people assume that their religion is "right" and that I'm some blasphemer that's "going to hell for *blank*". If your god didn't want me to do something I wouldn't have the capacity to do it. I have no problems with religion or any other beliefs, but when you try to shove this "info" down my throat because it's "correct", I'm going to do everything in my power to offend you due to you ruining an otherwise ok day.
People that ask for my opinion on something, then give me strange looks like I'm some kind of freak. "He doesn't share my opinion? How stupid is this guy?". They just never seem to realize that opinions differ and then just respect that, they have to make a big deal out of it and irritate me to the point that hearing them speak at all is an now something that makes my blood boil.
The way people act when I tell them I hate driving with a passion. "You don't like driving? That's weird, driving is awesome!". Maybe if we were 12 years old or something I might slightly agree. But as a grown man, I think I'm able to refuse to do something so trivial if I wish to. I don't need someone's opinion on why "driving is awesome", I hate doing it, so I don't.
Small dogs. It's a dog, it should be able to be put in the backyard. It shouldn't have to be inside the house climbing all over the furniture, chewing on my stuff, peeing/pooping on the floor if you don't take it outside every hour on the hour (my dog, a lab, has no problem holding it when in a situation where she can't go right away, but this little rat of a dog can't hold it for a fucking hour.), etc.
Screaming children that no one will do anything about. I see these little pricks in restaurants, planes, stores, etc. They scream at the top of their lungs out of selfishness, and the parents don't do a thing to shut them up. I don't care what the kid wants, make them be quiet. When I was little, if I acted like an asshole, I was punished. So many shitty parents nowadays won't do anything to punish their kids and act like anyone that does is a monster. Most people I know were physically punished as children and turned out to be great/hard working people, the people that weren't, aren't.
I could go on and on about the things that bug me, but they give me a headache just thinking about them.