People who whine but don't do anything to fix the situation - Shut up if you're just going to bitch and do nothing. If you spent half the energy you fume with your impotent rage on actually fixing the problem, you would have solved it. This is pretty common in the US. Nothing is ever good enough but when push comes to shove, they won't do shit.
Lazy people - It sucks when the work I have to do gets slowed down by a lazy dimwit who has to go through an hour ritual of doing irrelevant shit before they start working, which they barely do anyway. Usually is the type of guy that whines about "the man" but spends most of their day shuffling papers and clicking the mouse indiscriminately so people think they are working.
Incompetent people - I'd be embarrassed if something that had my name on it turned out to be a disaster. Yet these guys have no qualms shitting up everything they touch and then wondering why nobody likes them. Imagine that.
Fundamentalism - This applies to just about everything. If you're an extremist about something, you're probably an asshole. This applies to religion, politics, a certain concept, mindset, etc. Then when someone owns them on something, they basically turn into a tourette's like dimwit who is frothing at the mouth about how everyone else is sheep and how they are the shining light.
College grads - I worked my ass off, made friends, and got a job. However, it is the last semester of my school year and I'm amazed at the dumbfucks who didn't do anything outside of classes and even then, has a 2.4 GPA. Then they mewl about how people keep turning them down or the best salary offer given is maybe $35,000. Good luck paying back your huge student loans with your cell phone sales job at Best Buy.
Loudmouth Republicans - Since its college, most GOP people think it is a librul establishment. Therefore, whenever a discussion comes up, a right winger has to loudly pipe in with his shit. Even if it is unwarranted or irrelevant. I remember in one of my Environmental Engineering classes, a dumbshit kept talking about global warming being fake. Eventually people got pissed off at him talking about stupid shit that had nothing to do with the topic. In his mind, it is because the "establishment" objects to his views. No, you're just a loudmouth moron.
Racists - Don't blame black people because you suck at everything imaginable. Those Mexicans didn't take your job, you're just an incompetent distinguished mentally-challenged fellow.
Rich people - Not all but most of them feel like they're persecuted but have no problem shitting all over someone else if their life gets a minor inconvenience. Most of them can be very nice if you look or act like one of them. Fortunately I'm a clean cut honky so I don't have a problem but a lot of the comments they make towards others

Indie rock - No skill required. Just shit out something incomprehensible, have a lot of noise at the end, and talk shit about record labels. I've never seen such a messy and erratic genre. Unsurprisingly, this is where Wikipedia diagnosed Aspergers listen to the most. Even Reggaeton has more organization. I long for the days when nu metal was considered at the bottom of the pile. The bar for music these days keeps lowering. This explains the popularity of Death Cab for Cutie, T-Pain, and Lil Wayne.
I got a lot more hate to spew but generally, I've grown up disappointed in the world.