Well, most of our cereals aimed at children. Adult cereals tend to be marketed on fiber content, ability to make you lose weight, or the possibility of containing dessicated fruit bits to distract you from the fact that bran flakes taste like cardboard. There's also bizarre, utterly indigestible products like Grape Nuts, which has the texture of wet cement and sits in your stomach like a rock.

Children's cereals contain the maximum amount of sugar and artificial colors that can sneak past parental radar. (somewhat decreased from the heyday of the 1980s, as I can tell.) Out of this category, hands down, there's no competition for Reese's Puffs, which contains nothing approaching nutrition. It's candy masquerading as breakfast.