I'm the odd one out as I've hardly bought any boxed cereal (as such) in years and years.
I think the last one I had faint interest in was Puffins, and I presume that was sugared.
I'll agree with Chai re Quinoa, but I like Bob's Red Mill Farro slightly better, re my taste, but they both are amenable to a lot of varied recipes. I even put farro in my burritos; haven't tried quinoa in them yet, but will. For whatever reason related to my taste buds, etc., I've never been interested in oatmeal for breakfast, and, way back when, I tried several types of it, all of it gah to me. I do like to use it in baking bread or in cookies or pancakes, just not as slime in a bowl or less cooked s.i.b., not meaning to offend those who are fine with it.
We all have our peculiarities.
I'd rather have good bread toasted and eggs, or good bread toasted, with hummus. I don't put sugar in my breads except for the wee smidge to get the yeast working full time.