If you want lots of princesses I would do the princess breakfast at Akershaus (Norway in Epcot). When we were there Belle was the greeter and we saw Snow White, Sleeping Beauty, Jasmine and Mulan.
Another family favorite for us is 1900 Park Fare for dinner. Characters are Cinderella, Prince Charming, Lady Tremaine, Druscilla and Anastasia. The characters here are absolutely hysterical and we really like the food.
We also like 1900 Park Fare for breakfast. Again, food is really good. Characters are Alice, Mad Hatter, Mary Poppins, Tigger and Pooh. The Mad Hatter is really funny.
Chef Mickeys is great for the characters (Mickey, Minnie, Donald, Goofy & Pluto). The last couple of times we've been there though the food has just been ok. (It was dinner.)
We also like O'Hana for breakfast. Characters are Mickey, Pluto, Lilo and Stitch. Food was very good.
We've always had good food at Crystal Palace (both breakfast and dinner). Characters are Pooh, Tigger, Eyeore & Piglet.
The last two times we went to Cinderella's Royal Table we felt really rushed and the food wasn't good at all. Considering the price I doubt we'll go back again.
If you're only going to do one princess meal, I would do the princess breakfast since you see the most princesses there. For my other two I would do Chef Mickeys and Crystal Palace as the characters here would appeal to both the boy and the girls.