Jumpin said:

I don't think any video game music has ever scared me before.

Recently, I played Metroid, and the music was a little unsettling in its simplicity. It is a lot different from other NES games.

Secret Area is a good choice, but Norfair Theme is more sinister than scary.

Here's the Witch's theme from Left 4 Dead.

Destroyah's theme from Godzilla Unleashed.

Opening to Hell from Doom II.

Metamorphosis from Metal Slug 2.

Also, can someone please move the thread to Gaming Discussion? I put it in Nintendo Discussion by mistake.