for me its that pre-firework music at the magic kingdom, I cant describe it but just remembering it gives me goose pimples
I love all of it I love the way music is piped around the parks, I often think it would feel like a different place without the music. I loved the music that is playing around the resort at POR, really nice in the evening when you are taking a stroll around the resort.
Of course I also love the music at all the shows and fireworks, I even like It's a Small World
Illuminations, EPCOT background music, the Main Street Electrical Parade music, the music that is featured in the different countries... I guess I'm an "all of it" person too!