contramacious
Adjective describing someone who is persistently argumentative and contrary; someone who will always, always find some way to disagree with whatever you say just for the sake of it. Often associated with a short temper and with total logical disconnect.
Bob: So yeah, I hate those darn fundamentalists.
Dave: Yes, they do tend to be a tad small-minded.
Bob: WHAT? Are you saying you hate religious people?
Dave: Er, no...
Bob: Because my mother is religious, you know. DO YOU HATE MY MOM?! WHAT THE HELL?!
Dave: ...You're such a contramacious jerk, aren't you?
Dave: Yes, they do tend to be a tad small-minded.
Bob: WHAT? Are you saying you hate religious people?
Dave: Er, no...
Bob: Because my mother is religious, you know. DO YOU HATE MY MOM?! WHAT THE HELL?!
Dave: ...You're such a contramacious jerk, aren't you?