My pet-peeve, as described below in my maximum detail, sophisticated diagram, in which I used the superior editing features of MS Paint to create the sophisticated, maximum detail diagram:
After sitting down and thinking about it, this may be first (of many) to place on this list:
Redneck, trailer-trash, more often than not who are chavish in nature, are on my "BIG LIST OF CRAP I CAN'T STAND." More often than not, their nature matched with their smell makes me want to kill myself while at work...