Cousin Vinny?

That episode worked on so many levels. Wow. The parasite conceit not only works within the show, but as a meta-concept as well. Rick is able to conjure up fake memories: "Lick, lick, lick my balls! haha remember that? I say that all the time!" (Also aware that this is a Doc and Mharti reference). While it's making fun…

Kill List and You're Next were great. I did enjoy Cabin in the Woods quite a bit, but it doesn't deserve the throne at all.

Many amazing horror movies work as both, or at least have a tongue firmly planted in cheek (The Guest, The Loved Ones, etc.) I feel like the line has become blurrier and we can throw them all under horror for filing convenience.