i dunno about the ""best"" but i love the og "cabin fever" movie. who doesnt love a campy movie centered around some weird, infectious, gory disease? i also recall watching "we need to do something" half asleep at a sleepover a few years ago after everyone else passed out and i remember being very uncomfortable (i do not like being trapped). and on that note of people being locked in bathrooms: the og saw is great, too, lol.

see also: some gothic spanish period piece i dont remember the name of.