Jeez, I did not see this topic earlier.
I absolutely like VG music for being so diverse. There are many soundtracks which I enjoy to hear, but some of them which popped up in my head just now are:
Secret of Evermore: This game would not have been as memorable for me without it's atmosphere music.
Metroid Prime 2: Echoes: All 3 Prime games have some very good songs, but I gotta pick Echoes because it had the best music for me. Especially Torvus Bog. That is one of the few songs where I imagined just thinking about how great it would be to walk around such an area in real life.
Killer 7/: This being my 2nd favorite singleplayer game, Killer 7 has one hell of an interesting wacko soundtrack. Russian Roulette, Blackburn, Sweet Relief, Tecks Mecks and Dissociative Identity are some of the best.
Blaster Master:: I get goose bumps when I hear that 1st stage music playing. What a classic game.
I also love the many obvious favorite soundtracks to Castlevania and Mega Man.
These were just the tip of the iceberg regarding VG soundtracks which I enjoy to hear.