No particular order
-People who mix up Your and You're. If I read a sentence, and they mix this up, then I skip whatever else is written. I can't stand people saying "your stupid" or "I fucked you're mum". Dumbasses.
-Losing. I admit I'm overly competitive. If the outcome is decided by human choice, then I can live with it, but sports, video games and such, if I/my team loses, I become depressed and angry for a good 12 hours.
-Cocky sports fans. Particularly glory supporters. If you win, then I expect (but still hate) a little bragging, but those that boast on the achievements of their team, especially if you only supported them for a small time, are incredibly frustrating. Ignorant twats.
-Cheaters. If you're having a casual game of football (soccer), don't use your hands. Don't ruin everybody's fun. Wankers.
-Abbreviations. Particularly "u". Assholes.
-People who use violence to get their way. Tossers.
-People who use internet slang in real life conversation. Don't say "LOL" to me face to face or I'll kick you in the arse. Dickheads.
-People who pronounce H wrongly
-Classical music. WHAT IS THE FUCKING POINT OF LISTENING TO THAT CRAP!?
-Spoilt kids. Arrogant cocks.
Aside from that, I'm quite a happy guy