I love (roughly in order of preference):
Sweet Potato Pancakes at the Wave (and they have an optional buffet if you have a big appetite). Walk there from the magic kingdom!
Tonga toast at Kona.
'Ohana is my favorite character breakfast: lilo, stitch, Mickey in an aloha shirt. All you can eat, but not buffet, so you won't miss characters.
Breakfast lasagna at Crystal Palace. But if you're not into Winnie the Pooh, it probably isn't worth that big a chunk of your MK time.
Boma is a wonderful buffet with some African flavor, but plenty of standard breakfast food to fill you up too. Kinda hard to get to on Disney buses, but should be easier with animal kingdom's newly extended hours.
Captain's Grille is delicious, but really hard to get to from pop on Disney buses before park opening. You kinda have to beg a bus driver to take you there.
Cape May is equally difficult to get to. And the breakfast food is boring. Equally boring to 'ohana, but I prefer family style over buffet.
Whispering Canyon has a nice all-you-can-eat breakfast skillet and yummy banana-bread French toast, but tricky to get to before magic kingdom opens. But once the boats start running, the trip to Wilderness Lodge is a joy!
Grand Floridian has boring but well-prepared breakfast food, and the park fair buffet is an easy way to meet Mary Poppins. The Grand Floridian cafe seems to have the same food, but made to order.
Oh, and lastly Olivia's at Old Key West. Key Lime hollandaise! Probably not worth long bus rides from Pop.
Add in the cafeteria-style food at the value resorts, and that's all the breakfast food I've ever eaten at Disney! I love it all (except for those cafeterias)!