Girls or Boys?
My teenage girls love the fireworks shows. They will turn out every night for Illuminations, or work out that they can see Wishes/Fantasmic at 7:00 and then race to Epcot for Illuminations at 9:00. They also like "Who wants to be a Millionaire" (will play several times in a row) and the Streetmosphere characters at MGM.
At Epcot in Innoventions West there is a "Dance Dance Revolution" where you follow a monitor with Disney characters and dance to Disney music. They can do this for hours at a time.
Otherwise, they just want to ride the fast rides like Rockin Roller Coaster, TT, Mission Space, Test Track, Mountains at MK, and Dinosaur over and over again.
I would seriously consider letting them go off on their own for parts of the day, setting up a meeting spot for a later time. Better yet, have cell phones or walkie-talkies to keep in touch. Then you can do what you want without riding Dinosaur three times in a row!