OK, here's a list of slightly more cult horror movies. You'll be kicking yourself for not seeing/owning these already.
1 - Suspiria (jesus h christ...what a masterpiece. Surely Argento's best. The nano-second flash of witches shadows flying in the town square before the dog turns on his blind owner is horror in its purest form.)
2 - The Changeling (come on, what needs to be said about this one. Just brilliant, brilliant, brilliant. It's the Citizen Kane of horror).
3 - Ringu (yep, original all the way. It's 'nauseating' to watch just because it's so warped and at times non-sensical. Hideo Nakata pushed the envelope all the way, even if he did rip off The Changeling. The US version was an exercise of restraint, totally washing out all the grime. Even the "video" in the US version made sense, and what was that shit about the horses? Blech. Go with the psychotic Japanese hysteria)
4 - The Beyond (Fulci's best and certainly the best of the "splatterfest" films. Total gore all the way, without exploitation a la Cannibal Holocaust. The blind woman on the causeway is wide-lens cinematic genius, but the final portrayal of the desolation of hell is spectacular. The dog turning on the blind woman is complete tribute to Argento)
5 - The Devil's Backbone (forget the tripe that was Hellboy and go see this from the same director instead. Cinematography cannot get much better, no shit. And the small amount of CGI needed to show the dead boy surrounded by water as he roams the halls is perfect. Nothing OTT about this flick, just dark, ambient, and mournful).
6. Don't Look Now (setting this film in Venice was genius. It's a total gothic affair and it's got Donald Sutherland for crissakes)
7. Exorcist III (fantastic horror "thriller" totally worthy of keeping the Exorcist name in the title, with the whole Gemini Killer thing going on with Karras in a straight jacket...holy shit).
Probably forgot a few.