Favourite game music

Most of my all-time favorites are from the C64, since that's what I grew up listening to:

Commando - Rob Hubbard

Crazy Comets/Mega-Apocalypse - Rob Hubbard

Nemesis the Warlock - Rob Hubbard

Robocop 3 - Jeroen Tel

Stormlord - Johannes Bjerregaard

Turbo Outrun - Jeroen Tel

I could go on for hours.
It mightn't be the BEST game music, but I love the music from Snatcher. Cos you're just looking at a still image half the time, it plays a bigger part than normal I guess atmosphere-wise. Actually, I really like the music on the MSX Metal Gear too so maybe it's just whoever Kojima get to do the music (if it's the same person).
Streets of Rage 2

Ridge Racer series

Dracula X (PCE)

Dracula X (SAT)

Metal Gear 2

Grand Theft Auto

Radiant Silvergun

Thunderforce III

Battle Garegga

Jet Set Radio

Sonic 1&2&3&Knucks&CD

Sonic Adventure 1&2

well..there are too many good game soundtracks...don't remember all of them
Aye, Super Metroid was one that came to my mind as well. That and the ambient sounds made good use of the 8-bit Sony SPC700.
Yeah, Super Metroid has some great stuff. Nothing I'd listen to outside the game, but it's perfect while playing.