I found "5 Days A Stranger" quite creepy.
Oh, yeah, you're right! I totally forgot about Yahtzee's horror series. Those were made before he did that whole Zero Punctuation stint. I used to be an aspiring AGS developer, and his games used the engine extremely well (his and the Ben Jordan series by Grundislav).
I want someone to make a game based on eighties slasher flicks where you play either a victim trying to survive against an AI killer and keep as many of your friends alive well while getting naked and doing stupid things, or you can play as the killer and hunt down the AI controlled stupid hot naked people with various objects. Of course you'd be expected to freak them out first if possible.
The closest I think you'll get to that dream is Clock Tower, though there's no nudity and you can't play as the killer. Everything else you talked about, though, pretty much describes Clock Tower.