Well don't let me stop ya, but cool thread idea...
For me it was the original Wolfman movie starring Lon Chaney. Scared the crap outta me as a kid. I had a recurring dream about the wolfman chasing me around a pile of construction debris that was in a field near our house at the time. After a few times I realized in the dream that it was obviously a dream because I was able to outrun the wolfman. The fact something could create such a mental response fascinated me. From there, I took an interest in special effects and creature makeup. I still do today. My son is also in a magnet school arts program for special effects and film making.
The Hoss household does a huge Halloween scare house every year that is on par with pro level theme park presentations. 2 of my kids have been performers in the Busch Garden How o Scream attraction. A few more of the friends that help us are also performers there or at Universal Halloween Horror Nights in Orlando.
Ironically, the wolfman makes an appearance every year, but only his severed head on a spike in my wraith's graveyard. Perhaps a subconscious desire to remind myself I conquered him?
Anyway, yay horror flicks!!!
BTW, I recently saw the flick "Green Room". Though not strictly technically "horror", it was pretty good. I'd recommend it.