I know that music stimulates the brain.  Listening to music can cause one's brain to flood with memories of times past.  Wonderful experiences.  Horrible times in one's life.  Break ups. Parites.  Concerts.  Long drives. Video games.  Lots of things.  There have always been games that I played where music played a large part of the enjoyment of my experience of that particular game.  As many might mock it, Deadly Premonition was far more enjoyable because of it's music.  I bring this up as a particularly more relevant addition to games I have played where the music transformed the experience, making it one that could have been, oh let's say, mediocre at best, but was transcended into a higher level of greatness because the music was so enjoyable.  Impeccable, even.  (Who would have thought jazz could so infuse a game with such influential sax riffs?)  I can still hear the opener to The Secret of Mana from the SNES and get warm feeling in my loins.  I love it.  It reminds me of a less stressful time of life.  It also brings back the joy of playing that game.  The Legend of Zelda: Ocarina of Time still has music that will randomly pop into my head many years after I originally played it.  It is an important aspect of the whole process of absorbing the gaming experience and is one that I always look forward to.  What do you guys think?  What is your favorite game music?

GTA: Vice City is my favorite game soundtrack, San Andreas' Soundtrack was pretty good too. Once I was in Florida and I knew all of the lyrics to a shitty Southern song because of San Andreas, I found that really funny at the time. 

" GTA: Vice City is my favorite game soundtrack, San Andreas' Soundtrack was pretty good too. Once I was in Florida and I knew all of the lyrics to a shitty Southern song because of San Andreas, I found that really funny at the time.  "

Being a metal fan i thought the Blazblue theme totally rocked. MGS4 also had one of the most epic themes ever as well as Bioshock 1 and 2. Who thought crazy splicers and 50's music would be such a great match?!

I'm with you, Ocarina of Time songs are always in my head, and it's excellent. Also, listening to all the music in Persona 4 makes me think about the Endurance and become sad that it's over. That's probably because all the songs play so many times that I've definitely heard over 5 hours of each song in the game. I'm sure it'll be the same with Persona 3 once I'm finished with it.

Anybody notice that the Mafia II soundtrack is BITCHIN??

I love game's music too, and have several favourite tracks, but the one i like the most is probably Silent Hill 2's Promise. 
 

" @Jeust:   I understand.  There is so much out there that requires my attention now, getting back to old games like that, unless you are in the industry and do nothing but play games....it is difficult to do if you want to keep up.  "

" @supermike6:   I haven't played any of the Persona games and I haven't watched those Endurance Run's yet.  Worth checking out? "

Best Licenced Soundtrack probably THPS2, it just worked.
 
But by far the best original soundtrack has to be The Suffering. Not music, just super creepy ambient sounds made from everyday stuff. And there's a video in the game that shows you how they "composed" it. You should really check it out.

It's hard to pick favorites when game music is one of the few things in games that are almost consistently good.
 

I adore the Halo soundtrack. So, so much.

Kelly Bailey <3

The Final Fantasy Piano Collections are among my favourites aswell, especially X-2 by Noriko Matsueda and Takahito Eguchi.

Wind Crest - The Three Trails is played at least 3 or 4 times a day.

Most Final Fantasies had great soundtracks, I liked Halo (off the top of my head). Koji Kondo goes without saying.

Quake stands out to me. Trent Reznor did a fantastic job with that.