I am speaking here of "rides" versus theater presentations. By sound design, I would qualify that as both music, song, sound effects and dialogue working together, and you can be as specific (a certain scene or area of a attraction, or even specific sounds) or general (a whole ride's audio components.)
My favorites would have to be:
1) The Matterhorn. I am at times tempted to burn a whole cd of just the area tracks and ride sounds, it would be quite relaxing I think. The wind whooshing effects and the ice cave "tinkling" noises along with Harold's growls and roars are very atmospheric and well done, I love just stopping to listen to them especially at night and I am around that area of the park.
2) The Haunted Mansion, portrait hallway and the corridor of doors. The portrait hallway is a personal favorite, with the thunder and lightning and almost subliminable arrangement of grim grinning ghosts via the wind, and the subtle chiming bell noise. The corridor of doors is another favorite, with the cries from the man trapped in the coffin, the knocking and banging, and various moans, screams, and laughs even though some are bit cheesy.
3) The now-extinct Haunted Mansion attic, with the wedding march on piano, the I-Do moaning popup heads, and the much louder beating heart sound effect.
What are your favorites?