Voted WW/CF, really liked some of the hour tracks. I'm not completely into the NL music yet, perhaps I've not played it long enough, the hours sound so similar!
Wild World is just so nostalgic. Whenever I hear the music when my younger sister is playing it, I tend to try to play with her. (with no avail, because the is an independent little seven year old) I do think New Leaf has a better soundtrack though. Especially the 11p.m. music. That's my favorite hour in the game.
Having played New Leaf, Let's Go To The City, Wild World, and listened to Gamecube (which I've actually ordered, alongside a controller and save card for the Wii) I can honestly say the Gamecube version sounds very nice.. I actually love all of the music in a different way. Wild World is soooo nostalgic for me.. I remember my old town; ' Dump ' from when I was very young.