The current fad is to book Slinky Dog Dash at Hollywood Studios, Frozen Ever After at Epcot, FLight of Passage at Animal Kingdom, and (your choice of three) 7 Dwarfes Mine Train, Space Mountain, Splash Mountain, Peter Pan, Big THunder at Magic Kingdom.
Hottest second choices, if the first choice is unavaiable at the desired times or at all, or if you got motion sickness on the ride in question before, are: the others mentioned in the preceding replies.