Some suggestions.
The European/Japaneese soundtrack of Sonic CD has some pretty good tunes. Recommended: Cosmic Eternity, Stardust Speedway, Metallic Madness, Palmtree Panic and Final Fury. (Available in Sonic Retro.)
All versions.
Kingdom Hearts saga (If you're into violin/piano music.) Recommended: Destati, the other promise, deep anxiety, another side.
Super Smash Bros. Brawl (Even though the majority of the songs come from other games, they are played in a majestic fashion.)
Recommended: Tabuu final battle and give the rest of the songs a go.
Ace Combat 4 & 5: The final mission song for both games is superb. The rest of the soundtrack is very good too.
Half Minute Hero: In case you like heavy guitar riffs and the such, the introduction song is perfect for you.
Sonic Generations: It has the best of the best when speaking about Sonic music.
Recommended: Chemical plant zone, City Escape, Crisis City, Rooftop Run and Planet Wisp.
The rest of my suggestions have already been mentioned. (Maybe.)
Megaman X series.
Castlevania (entire series, emphasis on Symphony of the Night.)
Final Fantasy
Legend of Zelda
Mario Galaxy 1 and 2
Shadow of the Colossus
Ace Attorney meets orchestra
Sonic Adventure 1-2
Sonic Heroes
Halo 3
Hope this was helpful!