We LOVED the Sunday a.m. character buffet breakfast at the Dolphin's Coral Cafe, on the first floor near where you leave the building to get the boats to MGM & Epcot. The characters were Pluto, Goofy (our favorite), Chip & Dale. Since it wasn't too crowded, the characters spent a lot of time with our kids.
The food was superb - smoked salmon with capers, cream cheese & onions; made-to-order omlettes, Mickey waffles, delicious breads and pastries, eggs, pancakes, bacon & potatoes, bagels. Quality was very high. Pleasant atmosphere, great service.
The smoked salmon was worth the cost alone, if you like that sort of thing. The buffet is every day of the week but the characters are only there on Sunday.