Most Mark Morgan stuff is great and as Matewis above me said Fallout 1 and 2 are fantastic but so is the Planescape Torment music he did too imo.

Alexander Brandons work on Deus Ex 1 and the soundtrack of Mask of the Betrayer expac to NWN2 is stellar also.

Morrowind while perhaps not a soundtrack i would listen to outside the game, it still conveys the amotsphere of the game in a tremendous way.

Rik Schaffers VtM music is great also with very atmospheric ambience.

The Witcher 3 is a soundtrack i really like too.

Icewind Dale II - Skeleton of a Town is beautiful for real. Inon Zur sure knows how to compose music.

silent hill 5 music is pretty good too Good!

Outlaws OST
Vietcong OST

Diablo 1 soundtrack is still probably the best ever to me. It's just perfect.

100%

'Stones' from Ultima. Nostalgically I love the version from Ultima 7. But musically the version from Lazarus is best! Generally the soundtrack of the latter is really great!

Fantasy General has some nice classical music which I like to listen to from time to time.

And the Realms of Arkania soundtracks are used as background music in all our fantasy Pen&Paper roleplaying evenings.

(I'll use this opportunity to share two songs that aren't OST, but awesome covers:
Stones

and Diablo )

The menu theme of Battlefield 1942 and the beautiful song Divinitus from Rome Total War:

https://www.youtube.com/watch?v=irXQid4peS0

Oh I forgot, Carmageddon 2.

Honestly, I hated that song, and felt that it did not belong in the game.

I would rather listen to Finale Toccata; while it's overused in the game, it's actually a nice piece. You might want to listen to the whole thing (in typical play, you are likely to enter a save or load room before the music gets a chance to finish, only to hear it start over in the next room). Did you realize that particular piece is in 5/4 time?

There's some other great music in that game, including the tracks used in the Alchemy Lab, the Outer wall, and most of the inverted castle areas that Finale Toccata *doesn't* play in.

By the way, did you know that the game's soundtrack was written by a woman?

A more recent soundtrack that I adore is the one for Hollow Knight, which is a classical-style (actually more romantic-era style) that has some interesting rhythms that are more typically associated with modern music. (Example: One track starts in 5/4, then switches to 6/4 as soon as the melody comes in. There's also instances of things like hemiola there.)

Edit: That other inverted castle track is called "Lost Painting".

Got dozens or hundreds of fav OSTs at this point, hard to pick.

This is where I became aware of the fact that I had mastered the innermost secrets of Prince of Persia - Sands of Time's combat system...

https://www.youtube.com/watch?v=Uc3xULxgqW8&list=PL6649E8FCE8340113&index=18

Best song: Baba Yetu from Civilization IV.



Hold on, let me just pick one song from the 10,000+ from my collection.