1) The Carousel of Progress doesn't have much of a queue, but I love that little tribute video they play on the overhead TV's for the preshow. I think it's a really nice way of acknowledging Walt Disney, and they actually do a really good job of explaining why this show was so close to Disney's heart. It admittedly kinda institutionalizes the attraction, making it seem a bit like a museum piece, but the attraction itself really is pretty dated, and I believe the preshow video really gives it the needed context and really does a great job of setting it up. So it gets my vote for best queue at WDW.
2) The "lobby" of G-Force Records is no big deal, but for some reason I love the preshow video of Aerosmith. Its dumb, corny, and horribly acted, and yet I find something endearing that this band would appear in a Mickey Mouse theme park. Hard line rock fans say they've sold out, I think they know how to have fun.
3) Tower of Terror from the lobby, to the study, to the boiler room, is really impressive and immersive theming.
Honorable mention goes to Pirates. I think the Blue Bayou loading dock at Disneyland is far more impressive, and WDW's loading dock is pretty plain, but the actual queue down the dungeon halls with those skeletons locked in an eternal stalemate really heightens the anticipation, especially the first time you walk down it.
Here you leave today and enter the world of yesterday, tomorrow, and fantasy.