Our favorite character breakfasts in order (we did 6 on our last trip):
#1 - Tusker House - we loved the food, the characters weren't too rushed and it's really close to the safari ride so if your ADR is early enough you can be one of the first on the safari.
#2 - Ohana - great food, fun place and characters, early ADR's get you to MK early
#3 - Princess Breakfast at Epcot - really good food (love the cheesy potato dish), cold buffet with meats, salmon, fruits and pastries, Princesses (and we have two young girls so you can't beat that)
#4 - Crystal Palace - good food, love the omelet bar, great characters, pre-rope drop ADR walking toward Cinderella's Castle with hardly anyone around is awesome - great photo opp
#5 - Hollywood and Vine - good food, had some issues with characters not coming around, but we told a CM about it and the character was there within minutes and spent a good deal of time with the kids. Was so "uncrowded" that some characters came by twice.
#6 - Chef Mickey's - worst food of all the breakfasts we tried, characters were so rushed as was the entire meal/experience. We won't go back to this one.
Have a great trip!