MK - Tony's. Never again! (Did have a really bad burger at King Stephen's once, but we aren't counting defunct restaurants, are we?)
Epcot - Its actually certain dishes I'll never order again, like the Tamarind at Rose & Crown, or that new lemon dill salmon at Le Cellier. I don't like the food from Nine Dragons, though, plus bad CS. I thought we'd never get the check to begin with, and then another half hour before he came back with our cards!
DHS - Mama Melrose, hands down worst ever!!! Caveat - I've never even darkened the door of ABC Commissary. Any place that advertises putting lettuce and tomato on a Cuban sandwich is not a place I want to eat, ever, LOL!