Sleepaway Camp (1983)
“Sleepaway Camp” is fairly un-original for the majority of it’s running time but it has gone down favorably in the annals of horror for it’s bizarre twist ending. It’s really something and caps the film off in great fashion although it doesn’t neatly explain a few things and actually creates a few holes as well if you really dive into it. But no matter; it’s one of the better shock endings in slasher history.