One of the most underrated rides/attractions is at Magic Kingdom and it should be at every park. I'm talking about the People Mover.
The People Mover is a slow ride that takes you around Tomorrowland but honestly, it should be expanded to take you all around the park. In fact, why not have a station on the other side near Frontierland? It would be an easy on-off and offer guests an incredibly relaxing ride around the park.
While the ride is nice in Tomorrowland, every park should have a People Mover ride. It doesn't need to have a drop-off point at different areas and can be a single loop around the parks that gives guests a nice view from a higher level.
I can imagine taking it around Hollywood Studios and through Toy Storyland or navigating through Pandora at Animal Kingdom.
This is one of those wishes that simply won't come true. The money it would cost surely wouldn't warrant the expansion or the addition but after riding it for nearly the thousandth time I realize that I simply don't get bored and every time I wish it was longer or that they would just let me stay on it.
Some attractions may not be all that enticing and for many, the People Mover is that. My oldest son finds it boring and my younger kids think it is a great attraction for "old people." Maybe that is the case but having an "old people" ride like this at every park would give three more opportunities to make them ride it with me!