If the kids are not super-picky (nothing but chicken nuggets/plain burgers/buttered noodles/cheese pizza), Morimoto Asia and Jaleo have the most interesting choices, in addition to being more visually exciting compared to quite a few other signatures.
Otherwise Cali Grill is good because everyone should see fireworks from there at least once in a lifetime and the children's menu ranges from mac-n-cheese to steak. Plus, you can eat early and go back later for fireworks. I agree with NYCgrrl that CG brunch would be an excellent choice (and a really good use of dining credits). Getting a reservation is another matter! I wish they would add at least one non-Sunday brunch per week.
Ones that might have less appeal to children are Yachtsman, Citricos and Jiko (because they'd probably rather go outside and see the animals).
Le Cellier, Brown Derby and Tiffins are fine if you'd prefer in-park dining.