People who bite or clip their fingernails on the couch (where I sleep). 2 AM, wake up to a sudden stabbing pain in my side. Pull out a half-chewed fingernail. Disgusting. <_<
Generally, one of the biggest things that bothers me is when people will stare over my shoulder while I'm on the computer, especially typing posts on forums.
Oh, and the fact that I'm not getting my share of the economic stimulus this year because I was a Dependant for half of last year.