I think 
I found the following via Digg: M&M’s ‘Find The Horror Movie’ game. While I’m generally not into horror movies (my eega, in fact, is), I was still able to find 27 out of the 50. Probably peanuts for the movie (horror) buffs among us, but still fairly well for someone who, well, like um. Me.
Some interesting things: I don’t think ‘Alien’ is well-represented, if compared to ‘Twin Peaks’ (which you should be able to find rightaway). There are some no-brainers in there too (‘Pumpkinhead’ for example) or, what that giant fly in the background.
Update: Ha! Make that 30 out of 50!