Hi Andrea,
I personally would go for
Chef Mickey's or
Tusker House Restaurant.
There are two reasons for these choices:-
1/ Both offer buffet dining which means that there is a vast selection of food on offer and there will definitely be something that everyone in your travel party will like to eat.
2/ You usually get to see more Disney characters at these particular Character Meals than some of the others. Although characters are always subject to change without notice we have seen Mickey Mouse, Minnie Mouse, Daisy Duck, Donald Duck and Goofy at Tusker House Restaurant and Mickey Mouse, Minnie Mouse, Donald Duck Goofy & Pluto at Chef Mickey's during previous visits.
I would recommend making a dining reservation for whatever meal suits you best. My family tend be be up early every morning and so usually opt for breakfasts. We have however had dinner at Chef Mickey's in the past and enjoyed it just as much as breakfast.
If I can be of any other help, please feel free to ask me another question.
Wishing you a magical trip filled with memories which will last a lifetime!