The best music by far a video game was from the Lucas Arts video game called Outlaws. It is an old one, but the music sounds like it was straight out of a Sergio Leone western. It doesn't get cooler than the music in that game.
Ah.. a topic near and dear to my heart. I'll do this by generation like Anti. 8 bit Best overall soundtracks: 1. Mega Man 2 -- So many great ones 2. Ninja Gaiden -- Even today, I think the Intro sequence is the best ever. 3. Final Fantasy -- Meh.. I don't feel strongly about this selection. Could easily have been Zelda 2 or Bionic Commando. Favorite individual songs: 1. Kraid's Lair (Metroid) 2. Intro (Ninja Gaiden) 3. Wily Theme 1 (Mega Man 2) 4. Act 4-2, the Mine (Ninja Gaiden) 5. Snakeman's Stage (Mega Man 3) 6. Undersea Temple (Final Fantasy 1) 16 bit Best overall soundtracks: 1. Chrono Trigger -- got to give props where they're due 2. Super Castlevania 4 -- could easily be #1 3. Super Metroid -- wow! Honorable mention: Final Fantasy 6 -- has quite a few forgettable songs, but some gems as well Others -- Actraiser, Ys, Street Fighter 2, Zelda:LTTP, Secret of Mana, Yoshi's Island Favorite individual songs: 1. Zeal theme (Chrono Trigger) 2. Clocktower (Super Castlevania 4) 3. Overworld:Terra's theme (FF6) 4. Schala (CT) 5. Frog (CT) 6. Lower Norfair (Super Metroid) 7. Brinstar (Super Metroid) 32 bit Best overall soundtracks: 1. Star Ocean 2: The Second Story -- the Rena themes and the Energy Nede overworld music clinches it for me. The ending music is beautiful too. 2. Saga Frontier -- tremendously underrated game music-wise! 3. Xenogears -- I wanted to give it to Wild Arms, Einhander or Suikoden, but I can't deny Xenogears' excellence. Honorable mention: Wild Arms -- music fit perfectly with the theme Others: Suikoden, Einhander, Castlevania:SOTN, Final Fantasy 7, Um Jammer Lammy!, Lunar Favorite individual songs: 1. Rena (Star Ocean 2) 2. Energy Nede (Star Ocean 2) 3. Forgotten Times (Suikoden) 4. Upside Down Castle (Castlevania:SOTN) 5. Seto's Theme (Final Fantasy 7) 6. Men of the Sea (Xenogears) 7. Fire Dogs! (Um Jammer Lammy!) All the various battle themes from Saga Frontier I know I'm forgetting stuff, but that's a general idea of what I like and consider to be the best. BTW: Check out www.minibosses.com
Synth: Old Sierra games (Space Quest 4, Hero's Quest in particular, Leisure Suit Larry theme , games distributed by Sierra but made by GameArts -- Silpheed, Sorcerian), Loom (LucasArt). But you needed to have a Roland. Dragon Quest III and Rockman (Megaman) II - amazing what was done with just 3 instrument tracks and 1 noise track. CD: Metal Gear Solid
Both GTA: Vice City and GTA: San Andreas get my vote. As far as original music, Shadows of the Colossus has an INCREDIBLE score, imo.