i think that stanley would actually really enjoy horror movies because he is very much the type of person who is like "it's not real. it's a movie. i know it's not real, so why would i be scared of it. what do you mean this movie is scary, it's literally people acting it's not real" and so because of that whenever the losers have movie night he always chooses a horror movie.
and, im also imagining that he does this because richie DOES get scared of horror movies (payback for when richie made fun of him for being scared of spiders)
also!!! he finds out that patty ALSO loves horror movies so for their first date stan finds this drive-in movie thing that is playing horror movies all night, so he takes her there and they have a movie marathon together :3