Chewing sounds of any kind make me mad.
Gum especially.
Professors that go off on tangents
That one Republican guy in your class that feels the need to object to everything
In the restroom using the urinal and a guy comes in and uses the one RIGHT next to you like there aren't 15 others
Wet doorhandles in the restroom. Dry your hands, nasty's

Touching old gum underneath a desk on accident
Winter in cold states
Farting. Literally..get away from me
When a box of cereal or whatever is empty but the person PUTS IT BACK in the pantry instead of the trash?! wtf
When someone changes the trash bag but doesn't put another new bag in the can after?! wtfff
Someone sitting next to you at the theatre and rubbing elbows or Knees with you
ugh there's so many.