We often have weetbix as DS loves it & I say what ever works. I mix it up a bit, smashed banana, or diced peach or pear in it. He also loves it when I put in sultanas...he looooves his sultanas.
Otherwise we have veg on toast, he loves raisin toast, muesli is another favourite. Ahhh, sometimes english muffins, just tried crumpets recently and on special weekends pancakes.