We didn't do this, but I've heard good things about the Cinderella thing for girls.
https://disneyworld.disney.go.com/di...a-royal-table/
Crystal Palace (Magic Kingdom) is an excellent buffet where the Disney characters come around and visit tables. Great food, and great fun for little ones.
https://disneyworld.disney.go.com/di...rystal-palace/
Coral Reef Restaurant (Epcot) has a SICK aquarium that you can see from your table.
https://disneyworld.disney.go.com/di...ef-restaurant/
At TEppan Edo (Epcot) the Japanese chef makes your dinner right in front of you.
https://disneyworld.disney.go.com/di...ot/teppan-edo/
Sci-Fi Dine In Theater (HOllywood Studios) has great ambiance -- the tables are like 1950s cars, and a reel of terrible highlights from '50s sci-fi movies plays on a big screen.
https://disneyworld.disney.go.com/di...ne-in-theater/
And easily the best (from my kid's point of view) was the 50s Prime Time Cafe (Hollywood Studios). The waiters are hilarious. They spin everything upside down, acting ike grandparents, and telling the parents to keep their elbows off the table, etc., while coddling the kids.
My kids loved it -- mostly because Dad got stuck pinning a napkin to a doorframe -- WITH MY NOSE -- for like 30 seconds in front of the entire restaurant. The food is good too, and it's a fun, memorable experience.