Let's get the obvious out of the way, first, shall we? I detest CoD, GTA, Madden, most of today's music, especially pop and rap, most rap music in general, The Simpsons, Apple, Facebook, and Twilight.
Oh, you wanted less obvious things to be listed? Fine, but just for you.
Blizzard Entertainment, the newer shows on Cartoon Network, Xbox Live, American football, the current movie industry and its pretentious stars, and finally, most fast food restaurants (I eat healthy almost all the time, so they are my worst enemy in terms of quality to nutrition ratio).
But above all? I hate stupid people, especially the willfully ignorant.
EDIT: Jesus Christ, I just realized how much of a spiteful bastard I really am.