For a boy I would agree Chef Mickey or Crystal Palace. Both of these are buffets, and we have enjoyed both breakfast and dinner at both. We will be having Christmas morning breakfast at Crystal Palace!
Something a little different is Donald's Breakfastasaurous (too many letters, but you get the idea) in Dinoland/Animal Kingdom. It is a buffet as well, with Donald, Mickey, Pluto and Goofy. The atmosphere is like a dining hall on a archeological dig, so it's not as bright and cheery as some of the others. The food here was much the same as at CM when we went in Feb.
I agree lunch or dinner at the Garden Grill is great. It is a new found favorite of ours. It is a plated meal, but you can get seconds of anything. I also agree with the observation that the character interaction is awesome there Chip sat at the table and colored with DD for a bit!
My all time fav is breakfast at 1900 Park Fare - with Alice from Wonderland Mad Hatter, and two of the Pooh characters. Also Mary Poppins is generally in the lobby for meeting and greeting. This one probably not as much for a boy. This too is a buffet.
Dinner at Liberty Tree is great too. We enjoyed the basic food - and had wonderful character interaction from Minnie, Goofy, Chip, Dale and Pluto. We will be eating there before
MVMCP and 12/18
DD and I have successfully visited every character meal this year it has been great fun, and there were none that were not good, just differing degrees from good to excellent!!!
Enjoy your trip!