Black Christmas
Sorority girls have the worst luck in horror movies. In this one, a serial killer stalks, calls, and begins to murder the ladies of a local sorority house one by one. The sorority begins to band together to beat the killer, but nobody knows who the killer could possibly be. The real horror is in the finale.
Maniac
This is a little darker than that Maniac starring Emma Stone. No, this one is about a lonely man who is weirdly obsessed with mannequins, which is made worse only by his habit of repeatedly talking to himself. They say there is someone out there for everyone, but this movie doesn't make us particularly comfortable with that.