This:
is probably the king. Made me feel strange. Seeing a girl raped with a shotgun and then the trigger pulled... yeeeeeah. Something about it really fucked with me!
NOTE: DON'T WATCH THIS ON ACID.
NOTE:
DEFINITELY DON'T WATCH THIS ON ACID.
City of the Living Dead/Gates of Hell, Pig Chicken Suicide, Last House on Dead End Street, The Burning Moon, parts of Combat Shock, and Pig Fucking Movie are all examples of movies that have fucked with me a bit.