When we go to McDonald's I almost always get a Happy Meal. I am not happy with most WDW kids meals though. It's not the quantity of food I have trouble with, it's the choices. Some places have decent kids meals, but I find that most don't. I don't want hot dogs, mac n cheese, pb&j, or chicken nuggets. That rules out most CS restaurants right there. My DD5 doesn't usually want what's on the kids menus either, so we will often share an adult CS meal instead.
Sunshine Seasons at Epcot has good kids meal options, IMO. At the moment I can't think of anywhere else I'd order one. Maybe Pecos Bill's, I think they have a burger on the kids menu.