I really don't see much difference in breakfast food than any other food. I tend to eat a heartier breakfast than I do lunch with dinner often "grazing." I don't like a breakfast that requires a lot of preparation time.
Don't laugh but my top favorite breakfast food is bean soup. I make a big pot of bean soup, put about a cup worth in a bowl, and heat it up. Maybe I have a piece of toast too. It is a substantial breakfast and gives me lots of energy.
If I am really rushed, I have toast with peanut butter, and fresh or dried fruit (like a hand full of raisins, or an apple). Pretty soon the tomatoes will be ripening and I have grapes and blackberries outside so I will make some jelly or jam. Basically, I go for carbs (for quick energy) some protein (beans, or peanut butter to last you till lunch).
I just made a great simple bean soup with portabella mushrooms, onion, and garlic, and a bit of olive oil. Very Italian. I'll be eating that for breakfast all next week.
Basically, You can eat anything for breakfast, not just breakfast food. Cereal companies brainwashed people into doing that, but I don't see why it is necessary.