EVIL DEAD TRAP
Director Toshiharu Ikeda & Takashi Ishii (writer) this is an older tidbit from 1988 and is actually a very unique and impressive slasher film. Of course this is J-Horror so it does not have the average run down like the American slasher films do. The movie contains those weird twist and WTF moments that can on come from Japan, a true classic indeed.
Note: stay away from the sequels as they are utter garbage and a waste of time, nothing remains the same but the name.
Some Other worthy mentions are:
Audition
Junk
Zombie Defiance Army
Horror of Malformed Men
Ju On I & II V Cinema versions included