Silent Hill 2 and 3 (I’m not sure about 4) had PC versions. ObsCure was decent game with co-op features. White Day is pretty good, though it’s Korean and prone to crashing/bugging out badly as well as having a few obscure puzzles and partially annoying design, but if you liked Amnesia you should be able to enjoy White Day as well. For point and clicks, Darkness Within 1 is really, really good, one of the best Lovecraft-themed horror games I’ve played. The second is not bad, but I didn’t find it quite as good. Condemned: Criminal Origins is also very very good, and Call of Cthulhu: DCotE is great (though after acquiring the gun it goes downhill).
As for mods, Grey was okay, and Underhell: Prologue, what little I played it, seemed nice. Afraid of Monsters is brilliant. I’d also recommend Nightmare House 2. All of these are Half-Life 2 mods IIRC.
Also, your lack of Ao Oni and Ib disappoints me.