Magic Kingdom - Pecos Bills burgers
Epcot - Any of the countries, with Biergarten being my favorite
MGM - Mama Melrose
Animal Kingdom - Flame Tree BBQ
Downtown Disney - Wolfgang Puck Express
Boardwalk - Big River Brewing Works for casual, or Flying Fish for something a little nicer
If you don't mind the short walk from Boardwalk to the Swan, then I highly recommend Palio at the Swan!