For that age, I would recommend Crystal Palace and Hollywood & Vine. Crystal Palace has Pooh, Tigger, Piglet and Eeyore and they are very gentle with young children. H&V has June/Leo from Little Einsteins, Handy Manny and Agent Oso. Both these places have characters that are more popular with the toddler/preschool age.
The next set of favorites would be Cape May Cafe, Chef Mickey and Tusker House.
You didn't mention if you had boys/girls, so not sure if you want to include princesses.
I think you'll have a wonderful time at any of the character meals. I would go with ones that have characters that your children like and can identify with -- that makes it more enjoyable for them. Also, your choices will depend on your touring schedule because you'll want to minimize your travel times for dining.
Have a wonderful trip.