The moment you said consoles only, Assassin's Creed was the winner. If you include PC sales, that's a serious edge for Battlefield and I can't be sure which will sell more.
Come join our video game music rumble! Everybody is welcome!
http://forums.ffshrine.org/f63/official-video-game-music-rumble-66118/
We vote on our favorite music from various categories we have created. Currently doing: "Best PS2 Soundtracks". More to come!