Damn this is tough! Thought I was fairly clued up on horror but obviously not :D

Here's some of my guesses:

#3 The Fly (1986)?
#12 could be Faceless
#18 The Mutilator?
#21 Chopping Mall
#24 Dear God No
#26 Creepers/Phenomena?
#27 Land Of The Dead
#31 Night Of The Comet?
#35 Night Of The Zombies
#37 Night School

Im surprised Newb hasn't guessed nr 40 yet. ;)

I wouldn't mind finding out what it was.....because I would definitely watch it :D

doesn't look like anybody guessed it