At that age my kids were more into the "thrill" rides. Their favorites were:
MK- Space Mountain, Thunder Mountain, & Splash Mountain. They were ok with Pirates of the Carribean, the Haunted Mansion, Buzz Lightyear and Alien (which is now Stitch - they don't like it anymore).
MGM - Tower of Terror, Rockin' Roller Coaster and Back Lot Tour
Epcot - Test Track
Animal Kingdom - Dinasour, River Rapid ride.
While they did do the other rides and we saw all of the shows/fireworks, they really weren't "into" it anymore. We'd gone almost every year since they were little. Last year they revolted! We ended up at US/IOA, Busch Gardens, Seaworld and Wet n' Wild which were more to their liking. They love thrill rides and roller coasters. We did sneak over to MK for one night for the Pirates and Princesses party and they did have fun (dd-16, ds-14) but said they were glad it was just for one night.
If this is their first time there they will just be excited to be there and love everything. I was in my early 20's before I went for the first time and it was just "magical".