Hi Andrew,
Like you, my family has been to Walt Disney World many times. One of the reasons that we keep going back is that there is always something new to experience! Let me offer you some of my favorite special experiences at Walt Disney World.
Be sure to check out the
special events and tours at Walt Disney World page. This page lists some extra special experiences. Some of my favorites include a ride on the Characters in Flight tethered hot air balloon, a walk behind the scenes at the Land pavilion in Epcot on the Behind the Seeds tour, and a walk across a rope bridge and backstage at Disney's Animal Kingdom Park on the Wild Africa Trek. There are many experiences listed on this page. I suggest that you peruse it and see which ones look right for you and your family. Please do note that there are age restrictions on some of the activities.
Another possibility is to book a
specialty cruise. There are many different kinds of specialty cruises. My family and I have really enjoyed the fireworks cruises. You get to take a cruise with just your party, enjoy the calm serenity of the water, and then take in the nighttime fireworks shows at Magic Kingdom or Epcot from a unique vantage point in your boat. Please do note that due to weather, sometimes fireworks shows are canceled.
Finally, check out the recreation options at
Tri-Circle-D Ranch at Disney's Fort Wilderness Resort and Campground. I think that Disney's Fort Wilderness Resort and Campground is an amazing place! Tri-Circle-D Ranch offers many recreation options, including pony rides, horseback rides, and carriage rides. Please do note that some of these have age restrictions.
I hope that these thoughts are helpful for you, Andrew!