I'm resurrecting this thread before time can claim it because I can never let it die, apparently.
But I bring several spooky themes! From games I haven't played, but oh well.
Jurassic Park 2 (SNES) - Lethal Gas
This honestly one of my favorite spooky themes, and it's absolutely perfect for the level it plays in (I watched a playthrough of this game out of curiosity). This theme just oozes dread and isolation and I love it.
Glover - Overworld With No Crystals
Can't seem to find an upload that isn't so quiet, but ah well. This track, to me, is a classic spooky theme (I mean, it's a N64 theme, so kinda goes without saying...). It's a type of spooky theme I'd like to see more often.
And now for a game I have played (and should really finish one of these days).
Luigi's Mansion: Dark Moon - The Garage
So this is basically the theme to my garage. Actually not sure if anyone posted this, but a few reposts won't hurt anyone.
And because I mentioned XCOM last time...
XCOM: Enemy Unknown - Combat Ambience 1 (if there's an official name for this, I don't remember)
XCOM: Enemy Unknown is similar to Metroid in that it's technically not a horror game, but damn does it get really freaking creepy sometimes. The combat ambience is always an experience. You know the aliens are out there, but you don't know where, or how many, or what they are.
To say nothing of the stuff you find on some missions... Bodies wrapped up in some green substance, the corpses of animals (if you're in a farm or wilderness area), among other things.
And the less said about Terror Missions, the better...