Damn this is a hard one, I thought each stages in Colours were both equally good and none of them really ending up better than another.
I guess I really liked Sweet Mountain and Aquarium Park just because of listening to their music.
Sweet Mountain - Act 3 Music
Aquarium Park - Act 2 Music
okay **** it why is the sonic colours soundtrack so good
also please remember sonic is a sega franchise, this doesn't belong in nintendo games discussion(unless it's here for the mere fact Colours was a nintendo exclusive game, which i guess i understand).