Some small discussions have popped up in threads here and there, but in the spirit of the day, thought it could use its own thread.
Here is a few from me:
Return of the Living Dead
Evil Dead / Army of Darkness
Saw (Not huge fan of the series but with all the traps and the like could make for a good pin)
Exorcist
Alien(s)
Zombieland
Godzilla
Friday The 13th
There is plenty plenty more.....