When I think of video game music the first thing in my head is Halo. I still get nostalgia when I use the original Xbox disk and a really awesome guitar riff plays.
Recently however I've taken interest in DooM, Wasteland, The elder scrolls, Mass Effect, Dragon Age and others.
Fallout is an interesting case since it's radio is not an OST it is a licensed asset and when you have listened to it as much as I have it gets annoying real quick.
The fallout background music is ok but it's very subtle and hard to listen to outside of the game.