I think that my favorite ride queue is Mission Space. When you are in the room with the giant cross-section of the space shuttle, I am just in awe of how much stuff they fit in that thing! I also like Space Mountain's queue, until you are beyond the good stuff to look at. When I was young, the long tunnel with the 'warped' windows made me feel ill, but I love it now! I love all the posters in Phillharmagic. Star Tours and Tower of Terror are great. I like looking at the props on the way to the Backlot Tour, but it's always SO hot standing out there on the ramp.
Honestly, the best queue's in Orlando are not at Disney! The Mummy has a fantastic queue area. The queue preshow for Shrek 4D is fantastic. Men in Black has a great queue. Spiderman's queue is fun to look around at. Dueling Dragons probably has my favorite queue down there. It's never so full that you have to get stuck in the castle at all, but it's so well decorated and always so clean. I enjoy the queue as a 'haunted house' as much as I love the roller coaster at the end of the wait!