It's not really about the "vitamins and minerals", it's about the fiber and whole grains a cereal offers, as well as the general LACK of sugar, that makes a cereal be considered "healthy" by most standards.
I give my kids mostly General Mills cereals, only because they at LEAST are all Whole Grain, and that's important to me.
What my son is eating these days (he's almost 5), is:
-Honey Nut Cheerios
-Regular Cheerios
-Golden Grahams
-Fruity Cheerios (similar in taste to Fruit Loops, but SO much healthier!)
He does like Lucky Charms, but that is a really special treat type cereal, because it has lots of sugar, and he tends to just want to eat the marshmallows (don't we all!)
I really wish that WDW was not in contract with Kellogg's. Or, I really wish that Kellogg's would get on the Whole Grain bandwagon too. All they seem to do is lower the sugar in their cereals, but they are still made with bad carbs...