Prepare for the scarily long list of Internet pet peeves... (no offense to anyone)
-The pedobears that spam perverted stuff in the chat on Minecraft servers.
-The flamers in the YouTube comments.
-The trolls who make "10 Reasons Why (insert name of popular YouTuber here) Sucks" comments and then only list 5 or 7 reasons. 
-People who clearly aren't advanced roleplayers posting in the advanced section. No offense guys, but you should be able to judge your own writing level.
-When people put swear words in the title of threads.
-Perverts, in general.
-Haters, in general.
-Racists, especially the ones who spam YouTube comments with racist stuff.
-Cat Mario.
-This one level of Skylanders: Spyro's Adventure that I can't ever get past, even when both of my Skylanders have 10 levels (the max levels you can get in the 3DS version, which is what I play).
Now, for real life stuff...
-The stuck-up popular kids. Some of them are nice, but 80% are just... no. They think they're all better than everyone because they've been dating since freakin' Kindergarten, but their not...
-Bullies. I had my experience with them, and they suck. Seriously, if anyone reading this happens to be a bully... just stop it. You're ruining someone's life.
-When there's no more Dr. Pepper at the house. 
-When my little sister and her friends decide that they want to prank me and my friends by putting water on our feet. They woke me up at 2:00 a.m. with that one...
-This one guy who was in my math class last year that liked to poke my friend and sing in class. 
There's more stuff that I don't remember...