The Gamecube music will forever be my favorite, I just love it so much! I wish they had kept it at least for WW before making new music.
I love 1pm (CATS) and the song that plays when it rains :3 also the Harvest Festival song is really funny and weird. But really, I love every song from Population Growing and have them all on my iTunes >_>
7am in Wild World gives me good memories of fishing in the morning and then waiting outside for 10 minutes for Tom Nook to open so I could sell my fish.
Gamecube: The start menu and 3PM hosts all the nostalgia of getting straight home from school.
WW I largely played with the sound off, so I'm going for Go K.K. Rider.
CF: Christmas Eve.