Melissa,
You are hitting a lot of the great ones!
There are a few other buffets that you might like.
- Boma, at the Animal Kingdom Lodge, is fantastic. It is a lot of the inspiration to the Tusker breakfast buffet. It is a bit more of a chore to get to, but I think it is worth it! And what a great excuse to visit this magical resort!
- Biergarten, in Epcot is open for lunch or dinner. Better for dinner as it has entertainment then, this German buffet has atmosphere and plenty of kid-friendly food choices.
When you are looking for more popular breakfast choices, consider getting Tonga Toast at the Polynesian. You can get it at either
Kona Cafe (table service) or Captain Cook's (counter service). This banana-stuffed sourdough french toast is out of this world! This could be a great pre-Magic Kingdom day breakfast stop.
Other non-buffet meal favorites of mine for families with kids your age include
50's Prime Time Cafe (Hollywood Studios), and
Whispering Canyon Cafe (Wilderness Lodge). They are not buffets, but they serve great food, and better entertainment!
Keep those questions coming!
Have a magical (and delicious) vacation!