People who enter my room and leave the door open

Humans... All of you.

Txt spk, General stupidity, people who say they troll for fun, General Stupidity, Assholes, General Stupidity, and people who strawman the shit out of arguments. Also General Stupidity.

People who play music loud enough to hear on public transport. Normally who do that have a real bad taste for music too :P

'Where' instead of 'were,' 'of' instead of 'have.' Hate those so much

Kicking the back of the chair I'm sitting on.
Playing music so loudly through earphones that the whole room can hear it.

Smokers smoking in the public.