Games with soundtracks/music that you'll NEVER forget.

[pevergreen]

For me:

F-zero X (the 64 version.)

Mute City among others, simply amazing.

Fire Emblem (GBA series)
The attack music alone is beautiful

Legend of Zelda: OoT and Majoras Mask

Rock 'n' Roll Racing

Black Sabbath & others I can't remember, it was basically a rock album with a nice game too.

[Xiahou]

Some good mentions here.

I'll submit the Persona3 soundtrack. A very memorable soundtrack for a very memorable RPG.

[Pannonian]

Bubble Bobble
Tetris

[Ramses II CP]

I bring this game up every time there is a gaming music thread, but the Descent 2 sound track is unforgettable. It amps you up so much it's actually harder to play the game when it kicks in. It suit the game atmosphere perfectly, and it's the only game soundtrack I still listen to today.

Halo is worth a mention too, but it's Bungie's previous series, Myth & Myth II that I remember most fondly.

[Fragony]

Just about everything Homeworld, space so big, you so alone

[CountArach]

TETRIS!

[drone]

Master of Orion 2

The sound when the main menu flipped onto the screen at the start was the best.

[Jolt]

Metal Gear Solid. No doubt.

[seireikhaan]

Prince of Persia: Sands of Time

[The Spartan (Returns)]

You cannot have a thread about music in video games without this masterpiece. I have this on my mp3 and kick it on every now and then. The glory days of Duke, never forget.

Awesome theme. Definitely reminds me of the Dynasty Warriors 4 soundtrack.

Mute City among others, simply amazing.

Haha, I was looking for that one!

***
If you wanna be more nostalgic, try the Pokemon Red/Blue Opening.

Also Tenchu: Wrath of Heaven.
Sadame
Character Selection
Tatsumaru's Theme
Last Decisive Battle
Bamboo Forest
Oninage 3

*Updated first post

[Greyblades]

Civ 4 main menu music was quite good.

[Caius]

Civ 4 main menu music was quite good.

Yes. But Nothing is better than the whole Empire Earth I soundtrack.

[Martok]

The Total War series definitely tops my list -- particularly Shogun, Medieval, & Rome. There are very few games whose soundtracks grip me like those do.

I would also have to add two Star Trek titles to the list: Klingon Academy and Birth of the Federation. The former game's music is positively soul-stirring at times, and while the latter's soundtrack doesn't grab me emotionally per se, it is very atmospheric and feels appropriately "Trek-ish".

Finally, I must grant an "honorable mention" to the first two Command & Conquer: Red Alert games. While they don't have the epic feel of the other titles I just mentioned, their soundtracks still somehow seem appropriate to the setting, plus they do a pretty good job of making the player feel tense (in a good way) and that time is of the essence.

[FactionHeir]

I liked the Morrowind theme better than the Oblivion one. They were pretty much one and the same, except that Oblivion was a bit more modernized.

[Chimpyang]

Zelda - Overworld has to be a classic in my book.