I like lots of game music, sometimes even more than "regular" music. Pain from Xenosaga, La Passione Commuove la Storia (Suikoden 2 ending, even better as arranged version) and the arranged vocal Aeris Theme are some of my favourites ever, but the last one doesn't count here...
Other very honourable mentions:
Small Two of Pieces - as good as Pain, depending on my mood... those pipes in the beginning make me shiver and Joanne Hogg is an amazing singer
Stars of Tears - more uplifting, still good
Edge of Soul (SE) - no comment
Mihata no Moto ni (Sakura Taisen 3) - this damn song was playing 24/7 in every game shop in Japan when I was there, had to get the game
Geki! Teikoku Kagekidan III (ST3) - any version of this song rocks
the Shinto and computer shop songs from Power Instinct Matrimelee - possibly the best fighting game music ever
Just a Day (GT3 by Feeder) - I don't normally like them, but this rocks
You were there (Ico) - totally beautiful
Infectious Love (KoF: MI, Live House stage) - a DDR song in a fighter, thank you SNK
Lonely Rolling Star (Katamari Damacy) - 8-bit nostalgy
Eyes on Me (FF8), Melodies of Life (FF9), Suteki da ne (FF10) - can't deny the greatness
Memoro de la S^tono (FF11 opening) - only good thing about this piece of crap
lots and lots of DDR songs