Honestly?? Here's my take on it then...
We have not done ALL of the character breakfasts, not by a long shot, but we have done quite a few of them, and here's the one thing we have discovered.. the food is all pretty much the same. Yeah, there will be a few differences, a few unique items, but you will pretty much get scrambled eggs, bacon and/or sausage, pancakes, mickey waffles, fresh fruit, breakfast potatoes, etc. You can check out the menus by going to the Dining section up there ↑ and see if anything catches your eye.
SO. If the food is pretty much all the same, what it really boils down to is, what characters do you really want to see, and where do you want to be? Our favorite character breakfast is Crystal Palace, not so much because of the food (although the puffed French Toast is quite yummy) but because of location. Time your ADR properly and you can get into the park at 8 AM and have some marvelous empty-park picture taking opportunities as you walk down Main Street to get to your breakfast, then, after breakfast, there you are, already in the park, no waiting at the turnstiles with the rest of the masses. (Note: you still can't get into the rest of the park till 9, when the park officially opens, but you are just a step ahead of everyone else at 9, because you are already inside). This is also a good place for Pooh fans, and a good place to see Piglet and Eeyore, who can be hard to see otherwise.
Breakfasts like 1900 Park Fare and Ohana are good choices because they are opportunities to see hard to find characters like Lilo (Stitch too, but he isn't quite so difficult) or Mary Poppins. Akershus is good because you can get your Princess viewing out of the way without having to pay the exorbitant prices at CRT, and also because, like Crystal Palace, it puts you inside a park.
Chef Mickey is a fun location, and a Disney tradition for many and, well, its MICKEY for pete's sake... but I think the food quality has gone downhill a bit, sadly.
Cape May cafe at the Beach Club is another option - Minnie, Goofy and Donald in "Beach" costumes. I think there is a breakfast at Tusker House in Animal Kingdom as well with Donald in safari gear. We did that one 3 years ago, and it was quite unremarkable - again the only benefit was that it put us IN the Animal Kingdom pre-opening.
Good luck in whatever you choose - I guarantee your children will remember the characters, and NOT the food.
My kiddos, at Crystal Palace at dinner before
MNSSHP this year.
There was a large group of us, all dressed as characters from Peter Pan. The character interaction was wonderful; Tigger tried to steal "Captain Hook's" hook and run away with it, and my step-dad asked Piglet if there was ham on the buffet line. Piglet did the "staked through the heart" routine then walked away, shaking his head in dispair...