This whole thing is terribly disappointing for many reasons and thus I use my vote on the game itself.
I'm stuck in a four way tie between Carrie, Invasion of the Body Snatchers, Ringu and The Shining because none of those are the best version of their own stories.
So in the meantime I'm going with Texas Chainsaw Massacre.
P.S. Se7en is 100% horror.
ETA: I voted TCM out because it is awful, not some obnoxious pedantic point of whether it is horror.