Premise: I currently lack any health problems associated with too much sugar.
So when determining the healthfulness of cereal for me, sugar content is not much of an issue. What is relevant? Whether it's fortified with loads of vitamins and the like. All too often, the 'healthy' cereal isn't. It's pretty much just wheat (so, some niacin and/or iron + fiber and a little protein). The 'junk cereals', on the other hand, are pretty much always fortified with 25%+ DV of oh so many useful nutrients.
For me, for now, Frosted Flakes and Froot Loops are a healthier choice than Autumn Wheat.
Grape Nuts are an exception, but they're disgusting. Things like Total probably would be acceptable.