This discussion may contain spoilers!
Seeing as how we've got threads for Best and Worst games you've played, how about a thread for your favorite video game music? I'll start us off, and in no particular order...
Banjo Kazooie - Rusty Bucket Bay -- Theme for a level in an oily, grungy harbor, complete with giant cargo ship!
Battletoads in Battlemaniacs - Ragnarok Canyon -- The theme of the first level.
Chrono Trigger - Frog's Theme -- The theme of Frog, a knight cursed to assume the form of a humanoid frog. He has not forgotten his honor or duties as a knight, though.
Command & Conquer - Act on Instinct -- The most recognized theme from Tiberian Dawn.
Command & Conquer: Red Alert - Hell March -- The iconic theme from the Red Alert series.
Command & Conquer: Renegade - Command & Conquer -- A great theme for the first real mission.
Dark Chronicle (Dark Cloud 2) - Gundorada Workshop -- The giant facility where the secret weapon to fight Emperor Griffon will be constructed.
Dark Cloud - Gallery of Time -- A trip through time, traveling 400 years into the past to unravel the mysterious past of your 'rival'.
Disgaea: Hour of Darkness - Hystelic Kingdom -- An awesome upbeat military march from an awesome tactical RPG.
Disgaea 2: Cursed Memories - Etna Rock -- The rock theme for Etna, Demon Beauty Queen! (Japanese lyrics, though).
Doom - Hiding the Secrets -- The theme for E1M9 or E1M8, I believe. I forget which level exactly.
Earthworm Jim 2 - Title -- A snappy vocal theme with finger snapping and clapping. Difficult to describe, but just plain awesome.
Final Fantasy 5 - Clash on the Big Bridge -- The battle theme of Gilgamesh, fought on a long bridge that stretches between two continents.
Final Fantasy 6 - Dancing Mad -- The final battle themes. Four separate tiers, one awesome piece.
Goldeneye - Dam -- The music of the very first level.
Homeworld - Agnus Dei -- A sad choral piece, played during the third mission, where you return to your race's planet to find the surface is burning, and there are no survivors left on the planet.
Homeworld 2 - Battle 2 -- One of the many battle themes from Homeworld 2.
Jazz Jackrabbit 2 - Laboratory -- It's just plain cool.
Jet Force Gemini - Sekhmet -- One can really get a sense of the majesty of the mighty warship Sekhmet from this track.
Ogre Battle - Revolt (Thunder) -- An upbeat military march, played on many of the early missions.
Seiken Densetsu 3 - High-Tension Wire -- A fast-paced boss battle theme.
Space Station Silicon Valley - Battery Farm -- The theme for level 4.
Soul Blazer - Southera -- Pirate island music!
Tactics Ogre: Let Us Cling Together - Avilla Henya -- Played during a mission in the middle of the night, where you must defend a village from being razed.
Terranigma - Dark Side Field -- Played when the player is navigating the frozen wastelands of Dark Side (a world within Earth).
Terra Nova: Strike Force Centauri - NewHope -- Track played during missions on the planet NewHope.
Tetris - Music A -- The classic game's classic music!
Zool - Candy Land -- An unexpectedly awesome rock piece for a very strange game.
That's all for now... I've already listed far too much. What about the rest of you?