We've been several times, and my kids ABSOLUTELY LOVED the character meals. They're pricey, of course, but worth it for the experience, in my opinion. In particular, there's a breakfast thing at the dinosaur restaurant in the Animal Kingdom that is a "don't miss" for us. And with your girls, I'd definitely look into the princess meals in Cinderella's Castle in the Magic Kingdom as well.

Those two should be consistently offered, but other offerings have changed from year to year, so I'd look at the Disney websites for what the current character dining options are.