There's a lot of things (more so pet peeves) but for now these take the cake:
-Crying/screaming babies and kids, especially on airplanes and in bookstores/restaurants/anywhere where people vastly prefer sound peace. I recognize that it isn't entirely their fault but having sensitive hearing it really grates my ears when I hear those shrill sounds (I have misophonia).
-The Tumblr SJW crowd (and far leftists in general). To be fair I don't care for right wingers either, but the Tumblristas/os really grate my nerves with their hypocrisy, ignorance, and downright hateful nature
-People who militantly or fervently see their race, ethnicity, culture, religion, gender or political ideology as superior and that anyone who isn't 'one of them' is bad or lesser and anyone who is 'one of them' must automatically think, act, live and believe exactly as they do else they be branded a traitor or sellout. Or that anything their group says/does is right no matter the circumstance.
Mind you I hate the mindset, not the person(s) who hold such views
-Cluster B personality types
-The trend of unfinished games either being completed through Kickstarter funding/beta backers or through paid microtransactions/DLC. Especially fighting games. I grew up in the day of unlockables and the occasional expansion. Nowadays its just a pathetic cash cow and an insult to gamers
-Stupidity
-Jrpgs (except Pokemon, Dragon Quest and Final Fantasy). What irritates me more is that whenever I meet someone and we both agree we like rpgs, 99/100 the only rpgs they know are jrpgs
-Completely awesome looking games and concepts that turn out to be online or multiplayer only (wouldn't mind an in-depth, deep storied single player campaign set in the world of Aion, The Old Republic, City of Heroes/Villains, Champions, The Secret World, etc...)
-People who ask "Why are you so quiet?"
