Matewis: Oooh a point n click recommendation? Well allow me... (clears throat) ... wait a minute, does it have to be on gog, or is ii also okay if it is very high on the wishlist? It's okay you say? Well, then, the best point n click I've ever played, and indeed the best game I've ever played, is
Blade Runner. We also discussed the game a bit in a
gog thread I made back in january. It's not a horror game, but it does have a very dark and moody atmosphere.
If you really want to go for horror then consider if you will
Still Life. The atmosphere of the game reminded me a bit of the Johnny Depp film 'From Hell', or at least, half of the game reminded me of it.