I thought David Hammond's question below deserved its own thread. My kids like food brown and bland. I take them to Jim's Original's largely because I like it and because of the atmosphere (the polar opposite of the antiseptic, toy-vending burger outlets). About the food, they have little to say. The dogs are juicy and the buns are fresh.
The way our family accommodates our differing tastes is to find a couple of items that we know our boys will trust. They will eat chicken satay at Thai Aree, sweet doughy things at the Red Apple, pancakes or cereal at the Valois, etc. If nothing else they'll munch on bread (or tortillas or pita), and eat later. That way, we can still visit the neigborhoods (which is as important to our family as the food) and avoid fast food.
Occasionally, we'll do something especially kid-oriented (like the Choo Choo Restaurant in Des Plaines, Moretti's, or Superdawg) and, of course, there's Chicago's fine bakery and ice cream places (which we all enjoy). I expect that in time our boys will grow to appreciate more things.
It has always irked me that the tourist guides targeted at families invariably focus on some of our town's more mediocre spots (Ed Debevic's and the dreaded Cheesecake Factory being a heavy favorites), which are understandably convenient and non-toxic, but don't try too hard in the food department.
I doubt that my boys are ready to go to eat organ meat tacos at Maxwell Street, but they're excellent dining companions nonetheless.