Very hard to answer this question. It depends on whether you are willing to use 1 TS credit or 2. the better restaurants tend to require 2 TS credits. If you are willing to use 2 TS credits, I would suggest Jiko. If you are not as adventurous, I would suggest Brown Derby or California Grille. But it is mostly going to depend on what kind of food you like to eat. I would personally much rather eat ethnic type food or seafood than steak, so I gravitate toward places like Jiko or Flying Fish.
For 1 TS credit, if you are talking about a sit-down meal, I love Teppan Edo, but keep in mind that you are seated around a common table and the cooking is part of the process/show. It is not romantic in the traditional sense. Marrakesh or Tutto Italia are good choices for 1 TS sit-down meals. Many people here like Le Cellier, too, although I did not care for the ambience - to me it was overly crowded and seemed like we were in a basement. The restaurant in Mexico at Epcot has wonderful ambience, as does Coral Reef. Those get mixed reviews as far as food but we had good experiences there.
My advice would be not to worry too much about the reviews unless they are CONSISTENTLY negative. You will find that for every person that loves a restaurant on this board, another hates it. The best criteria for your family is what kind of food you like and where you want to be located that day (in a park, relaxing at your resort, etc.).
FWIW, Boma is my favorite restaurant on property, if you like buffets.
