Goofy's has great food, and a very wide variety of options - including the P, B & J pizza that the kids might like, worms and dirt, cupcakes, etc. - and they have increased their number of characters recently (though still not to the Minnie & Friends level), based on what I saw in December and have heard on the DIS recently. If you don't want to risk Ariel's Grotto because you aren't sure how the 10-year-old boy would feel about it, I think Goofy's Kitchen or Minnie and Friends will be the best for you. (In fact, I encouraged Clairabell29 and her family to try Goofy's last year and their family loved it.) But maybe Minnie & Friends - because it is cheaper and has more characters - might be the best for you. Or maybe Surf's Up with Mickey and Friends at the PPH.
Honestly, Storytellers Critter Breakfast is kind of boring as a character meal, especially for kids, I think. I mean, if that is the only character meal a child has ever done, then they would have nothing to compare it to and probably would like it. But I am convinced that Minnie & Friends or Goofy's Kitchen would be a bigger hit with kids if they had them to compare. Even on a day when the food is at its best (which it was not the last time I was there, in October), the mood is very laid-back at Storytellers and you have to be into Koda, Kenai, Meeko, Terk, etc., to enjoy it. I would rather try the new Surf's Up with Mickey meal at the PPH before I go back to Storytellers again. Fortunately, Chip and Dale are at Goofy's and Minnie's too, so I don't have to be forced to go back to Storytellers again to see them!!!