Indeed

VVVVVV


love the music in that game

The Void for sure !

And also :
Machinarium
VVVVVV
Hero Core
Super Crate Box
Cave Story
Fallout 1 / 2
Planescape: Torment
Amnesia / Penumbra
Rule Of Roses
S.T.A.L.K.E.R.

Edit: Also :
Silent Hill series
The Path
Another World
Super Meat Boy
The Longest Journey

And I'm probably forgetting a lot of good soundtracks...

It's interesting how, as video games have gained more respect as an art form, music has become more important.

Some really well-done themes:

Tom Raider
Halo series
Far Cry (oh my goodness, if you haven't heard this, the raw power is awesome)
Evil Genius
Duke Nukem Forever 2001 Orchestra Theme
Half-Life Valve full theme/Song Suit 3 :P


OSTs:
Rayman 2 (I was sad the OST from GOG was mostly short tracks) The Final Boss song, if acquired from YT, is 6 minutes of awesomeness.
Silent Hills
Simcopter/ Streets of Simcity (kinda generic but also some cool stuff)
NFS 3 and HP2
Pirates of the Carribean PC game from Bethesda (I believe)

(Usually there aren't any "full" OSTs I'd recommend, just various scattered songs.)

Songs I have on my Sansa mp3 player (most downloaded off Youtube):

Timesplitters Western song
Rayman 2 Woods of Light and Precipice and Barrel Ride
NFS HP2 Hot Action Cop and Bundle of Clang and Ordinary and etc
Just Cause 2 Theme
Just Cause OST Track 19 and Track 4 and Theme
Half-Life Valve full theme and Track 20
Lego Island OST (believe it or not)
Comix Zone - Night of the Mutants
Jazz Jackrabbit 1 and 2 themes
NFS MW Chase music
Portal ... song
Metal Gear Solid Eminence Symphony Version
Crysis 2 Epilogue (as well as BoB's song from the commercial)
Super Mario Galaxy Gusty Gardens
Wonderland Adventures Cave Forest's End (obscure indie game but some great music)
Test Drive Off-Road 3's full song list
Tony Hawk Pro Skater 2, 3, and 4 various songs
Simcity 2000 Subway song
Starcraft 2 Wings of Liberty song

The old SNK games still have some of the best soundtracks. They released arranged sound trax to almost every OST as well. SNK Sound Team forever!

Boss theme (AST): http://www.youtube.com/watch?v=O3zPE1g9eF4&feature=player_detailpage

Shakuhachi flute (AST): http://www.youtube.com/watch?v=UcetvBBdwWw&feature=player_detailpage

Staff Roll (AST): http://www.youtube.com/watch?v=nKaI6CFesuQ&feature=player_detailpage

Beyond Good and Evil has the greatest soundtrack of any game ever. Hands down.

The Gothic games, Super Meat Boy, Mass Effect (dunno, I just like it).

darksiders ( http://www.youtube.com/watch?v=wBsUHcSncFM )
dawn of war 2 ( http://www.youtube.com/watch?v=KXF6SvmbHow )

(yes, i am into theatrical music :p)

Best name for a song in this generation.

So many to choose from, some of the ones that stand out in my memory.

GUN: http://www.youtube.com/watch?v=eKoNKXUKKpk

Anachronox : http://www.youtube.com/watch?v=iTaLfiUJErs

Baldurs Gate 2 : http://www.youtube.com/watch?v=U88zyFLzIXQ&feature=related

Dragons Age : http://www.youtube.com/watch?v=n2VDHLWFrFo

Blade Runner : http://www.youtube.com/watch?v=YbXYknkhjQc

Icewind Dale : http://www.youtube.com/watch?v=w6WhjqYst4s&feature=related

Vampire The Masquerade Bloodlines : http://www.youtube.com/watch?v=kKYMUqckV80

Castlevania: Symphony of the Night

Also:

Final Fantasy VI
Final Fantasy IV
Chrono Trigger
Streets of Rage
Revenge of Shinobi
Master of Orion II
Baldur's Gate II: SoA
Neverwinter Nights

Personally

Command and Conquer
Halo 2 - Absolutely loved the music, so much in fact that i bought the soundtrack and still listen to it.
Neverwinter Nights
Terraria

Probably more, but cant really think of any more at the moment, plus im tired as hell and its 3 am....time for bed.

personally think it one of the best ever

Kingdom Hearts Dearly Beloved
Dragon Quest viii
Nier too

Lots of great stuff in here.

Meeting Ravel Puzzlewell in Planescape: Torment was absolutely freakish. The music was fitting.

http://www.youtube.com/watch?v=-i75DqFHdpU