These are my favourite sountracks: (no links, sorry!)

- diablo 2; eerie atmosphere, definitely my favourite..
- baldur's gate 1 & 2; epic!
- anno 1404; very calm and happy music
- witcher 1; beautiful folk music
- doom; bring on the heavy metal! :-)
- eufloria; calming..
- machinarium; sweet!
- syberia; very nice soundtrack
- morrowind/ skyrim; very good sountracks!
- divine divinity; moody..
- arcanum; a nice, full of strings soundtrack!

Edit: how could I forget the last two? :-P

I'm a fan of some of the 16-bit music from my SNES days...

Flashback - and [url=http://www.youtube.com/watch?v=vAek8B76y6g]ending credits.

Also Super Metroid (Full Soundtrack)

The Sims 2

Europa 1400

Crusader No Remorse: 'The Traveler'
http://www.youtube.com/watch?v=wwG5BJtZBCU&list=PLBDAB91E4CC58FFC5

Hexen II: 'The Enchanted Cathedral'
http://www.youtube.com/watch?v=NSN_UuTntRo&list=PLF169DB46035DE0A4

Outlaws: 'Sanchez the Outlaw'
http://www.youtube.com/watch?v=dFWOl9XoxC4

No One Lives Forever: 'El Dorado'
http://www.youtube.com/watch?v=E3PtMTIHMVw&feature=relmfu

Anno 1404: 'Crowned King'
http://www.youtube.com/watch?v=l8AovClBD1I&list=SPC78EAD6B32ADB608

EDIT: and a very hilarious one from Crusader No Regret:
http://www.youtube.com/watch?v=uejvBkXtGmM&list=PLBDAB91E4CC58FFC5&index=15

Beyond Good and Evil OST - Hylian Suite
http://www.youtube.com/watch?v=_p5dLckSz6U

Portal 2 OST - Turret Wife Serenade :)
http://www.youtube.com/watch?v=4anpiZjfR-s

Half Life OST - Ending Theme
http://www.youtube.com/watch?v=oy1lsys2leg

Half Life 2 OST - Lambda Core
http://www.youtube.com/watch?v=1v4882jPvyA

Fez OST - Adventure
http://www.youtube.com/watch?v=76GnOwHorn0

Monaco OST - Prison Life
http://www.youtube.com/watch?v=bfXenMtnchk

Beatbuddy OST - Beatbuddy Swing
http://www.youtube.com/watch?v=71XzIR7ZbLM

Rochard OST - Grinder's Blues
http://www.youtube.com/watch?v=QMit1cmh_1Y

Hedgewars OST - EarthRise Stage
http://www.youtube.com/watch?v=QkLRkyPhcSc

Battle for Wesnoth OST - Still Another Wanderer
http://www.youtube.com/watch?v=YSs0Y06nU0I

DOOM

https://www.youtube.com/watch?v=JxGzsJKg8zw

DOOOOM

https://www.youtube.com/watch?v=Sg37lkE5cuw

DUUKE

https://www.youtube.com/watch?v=BD3VJGDqphM

Blade...I mean Bloodrayne 2 :P

https://www.youtube.com/watch?v=KWUNkhPys4Y

Command and Conquer Hell March 2 (my favorite ^^)

https://www.youtube.com/watch?v=9WqwFhX6Cqg

Totally necroposting.... BUT!

Dear Lord the Darksiders 2 soundtrack is so good. Vey adventorous and epic at the same time. Some exaples:

A fight with "spoiler alert from the first few minutes of the game" song:
https://www.youtube.com/watch?v=txvZSL3DZ2I
It is unedited, so it does sound rough, in the actuall game, it adapts to the situation, so it sounds miles better.

A certail boss theme:
https://www.youtube.com/watch?v=O4lwpYLlVvM
Vey good. Actually reminds of The Witcher games for some reason (instruments used and vocals?)

The whole soundtrack is amazing. Plus, this game has the he most adventorous intro I had ever heard. In game it was just jaw dropping. Just gets you ready for slaying/puzzling/jumping and fighting stuff.

Great game. finished it a while ago, just now rediscovering the brilliant soundtrack. Get it, it is dirt cheap.

but its a good necropost !

ys first steps towards war

https://www.youtube.com/watch?v=yELuvkU32Lg

gynoug stage 1-1
https://www.youtube.com/watch?v=szh3iDfi9zU

Nightshade!




[url=https://www.youtube.com/watch?v=iU976kGLD_s ]Devil may cry [/url](Newest one.)

Chrono Cross.
I used to stay on the map and let this music run in the background, while doing homework.

awesome music on the zx spectrum

https://www.youtube.com/watch?v=68U0p4q20wc

Does anyone wanna Jam?

Hm won't search for links, but some of my favs:

Myst II-IV - The original had a nice one too but it lacked production value a bit, so i won't include it here. The others are amazing though, i like to listen to them when i get artsy ;)

Baldurs Gate - Throne of Bhaal, some very epic orchestral songs, really like them a lot

Planescape Torment - A bit odd and sometimes irritating, so it fits the game perfectly. I don't think theres a better bar song than in the Smoldering Corpse Bar, also the Main theme is really great, i like how there are several variations throughout the game.

Mass Effect 2 - Quite dark at times but it really fit to the game mood i think. Also, it just was totally epic at times. Suicide Mission theme for example.

The Witcher 1 had an amazing soundtrack, almost every track of it.

Bioshock Series - Not just the period songs but the original score as well, i really like the string pieces.

Honorable mentions:
DX, DX:HR, Unreal, UT... fits the scifi theme pretty well.
Both Alice games.
Gray Matter, although a bit more variation would have been nice
Stalker
Oblivion/Skyrim
Never played them but what i heard from the Silent Hill soundtrack was nice too. One of the best things about the movie at least ;)

Castlevania: Vampire Killer:
https://www.youtube.com/watch?v=C-azpF5LfuQ

DOOM E1M1:
https://www.youtube.com/watch?v=BSsfjHCFosw

Pokemon Emerald Vcitory Road:
https://www.youtube.com/watch?v=Obee0qtFYmI

Anything thats from shadow of the colossus :)
https://www.youtube.com/watch?v=VzfOGO0qJmA (11th colossi theme)

My Fav was Cybernoid 2 on C64, along with Ghostbusters