Well, I have a bunch. Around the walls of my home office though, I have four:
Texas Chainsaw Massacre
Bird with Crystal Plummage
I have Texas because it's just a brilliant film - one I underestimated for a long time. I watched it at first and thought, "Hm, kinda hyped up". But on multiple viewings, unlike most films, it got MORE SCARY. Weird.
Halloween is just a personal favorite of mine. I honestly think the original film is just about as perfect as a horror flick can get.
Event Horizon is a cross genre film that works on every level. I could watch this thing once a week and still enjoy it. It's a deep film, with unexpected turns.
Bird with the Crystal Plummage - well - this poster is great because it is red and black, and it has two huge black gloved hands reaching for an insert of a womans face. The black gloves epitomize gaillo - so that's cool.
I have tons in boxes too.