I need a cult classic horror movie?

yeh please could yhou reccomed one to me? ill tell yhou what i want; i want a movie that is really weird and has made people go to mental homes, maybe even having dark magic in the very tapes? i want something like beggotten or something,blasphemous, something that a lot of people have have critisized liek the exorcist, im not lookin for something thats just reli gory, i want a movie that is quite underground in a way, really artistic and etc. please could you help me owt?thankyou very much x