1. Sorority Row (2010) First off, I should say that I actually kind of love this movie. It is terrible in a really fun "logic doesn't matter" sort of way, and has some ghoulish kills. What it does not have, however, is respect for any of the female characters. So, here's what you do. Tell your friends that you are going to be bringing a movie called "Sorority House Massacre or something." Be sure to say, "It was written by lesbian feminist writer Rita Mae Brown, and is directed by a woman, too!" Talk about how you think it'll be an interesting deconstruction of the misogyny of slasher films. Then, on horror movie night? Put this fucker on.
3. Dreamcatcher (2003) Are your friends the sort of people who "don't watch Hollywood movies" and instead only watch capital f Films? Then perhaps they will enjoy Dreamcatcher, which you will describe as an independent film examining the co-opting of Native American culture. The actual film is about a group of pals who talk with insane made up slang, share a common bond because they once rescued a mentally disabled kid, and are soon attacked by flesh eating ass weasels from space.
5. Killer Klowns From Outer Space (1988) That said, if you have a friend that genuinely suffers from Coulrophobia (the fear of clowns!) then holy shit have I got a movie for you. Everything about this movie is amazing. The creators take the premise "clown aliens attack earth" and they take it much farther than you expect. Not only do they aliens look like horrifying clowns (the makeup in this movie is really great) but their spaceship is a big-top tent. They ride around in a tiny clown car. They kill people with pies to the face, wrap them up in cotton candy and drink their blood through giant loopy crazy-straws. There are funhouse mirrors! There is killer popcorn! If you are gonna traumatize your coulrophobic pal, then you might as well do it right!