We've done breakfast with Pooh at Plaza Inn and dinner at Goofy's kitchen. Both are highly recommended.
If you're going to Plaza Inn, make ressies for the earliest time and see if you can get into the park before park opening. THen have your breakfast and head on into the park at official opening time. The characters were great when we went. They spent time at every table.
Standard breakfast fare but included mickey waffles and omelette bar.
There was Pooh, Piglet, Tigger, Eeyore and Goofy.
Goofy's Kitchen for dinner is raucous (in a good way). When we were there in April for dinner on a Saturday night they had prime rib and a host of other great dishes. there is a kiddie buffet bar too with mickey chicken things, PB&J pizza and mac and cheese. Desserts were awesome too. Alcoholic drinks were put on a separate tab. They do the macarena with all the characters and kids.
We saw Aladdin and Jasmine, Brer Bear, Ghepetto, Mulan, Pinocchio, and Goofy.
Hope this helps. Have fun!