1900 fare dinner buffet was the absolute worst TS meal that my family ate at WDW.
Although Tony's wasn't much better and didnt care for Tusker House Breakfast either.
The worst QS meal was Mara at AKL - breakfast and dinner.
Having said this we usually really enjoy most of our meals at WDW - inlcuding CP breakfast, CRT dinner, LeCellier Dinner, Cape May Breakfast, Earl of Sandwich, 50s Prime Time, Olivias, Askerus Lunch, Chef Mickeys dinner, Boma breakfast, Chefs de France Lunch, Jiko,Starring Rolls Cafe breakfast, etc