In MK I would like to see a dark ride based on Atlantis.
Also, "Glacier Mountain" where you ride in an ice floe boat, the ride is an enclosed dome (nice and chilly!) with IMAX footage of Alaska all around you, and animatronic polar bears, seals & penguins. End is a plunge down a glacier like Splash Mountain.
In Epcot WS, add Greece and do a dark ride with all those cool gods & goddesses and other mythical creatures. Ancient Egypt as a country in WS would also lend itself to a great dark ride.
In general, more rides that a chicken like me can enjoy!