Ken and I like steel-cut oats or other hot breakfast cereals as a filling morning meal. I sometimes get bored of them, so I make some similar options for variety. I thought I'd make notes about some here. Look for a follow-up post containing more ideas, mostly grains besides oats made into less traditional breakfast cereals.
Quaker Old-Fashioned Rolled Oats I like some plain oatmeal sometimes. I make it with half water, half soymilk to make it creamy and vanilla-y. Sometimes I like to jazz it up and make a fancy oatmeal, like Apple Pie Oatmeal or Banana Bread Oatmeal. I've also been using it to make a ton of granola.
Nature's Promise Organic Steel Cut Oats (Stop & Shop's organic brand) This is the cereal that started it all (the advance cooking of breakfasts, and this post). The oat groats (funny name, isn't it?) are cut fairly small so it doesn't take all that long to cook, maybe half an hour, but I still make it the night before. One batch makes 4 servings, which are fairly small servings but quite filling, although I then have to find something for the 5th weekday. This is a classic breakfast, so not many fun surprises, but it is very versatile. You could top it with a variety of things, but I particularly like it with the hazelnut topping from the hazelnut muffins.
Bob's Red Mill Scottish Oatmeal This reminded me of cream of wheat, but with oats. It's basically ground-up steel cut oats. Definitely whisk it in or it will clump up and the middles of the clumps won't cook. I made this with half 1% milk, half water. As with the above, you could top it with quite a few things, but I liked it plain just as well.
Bob's Red Mill 5-Grain Rolled Cereal I decided to make this for myself one day, and since it makes two servings, I figured I'd give Ken the other half for the next day's breakfast. Not thinking about that last part, I made it with half water and half soymilk. Once I remembered the other half was for him I decided not to tell him and instead to see how he thought it was. He LOVED it and I'm just never going to tell him it's made with soymilk. (I want to try this trick with some other cereals too.) At first I didn't want to tell him, but I let it slip after a while and he liked it so much that he was fine with it. This one is used the most in my kitchen (after regular rolled oats), and as a plus, the rolled grains are great in granola, granola bars or oatmeal cookies instead of just plain rolled oats.
Bob's Red Mill 10-Grain Hot Cereal I first bought this cracked grain cereal for the Banana Cereal Muffins in Good to the Grain (it's the cereal, of course) but I've also had it as a breakfast cereal. I mixed in a dollop of honey, that's it. Very tasty.
"Grandma's Grain" This is a recipe I've been meaning to try for a while, and I'm glad I finally got to it. I followed the directions, using red rice (from the last-ingredient options). I found it was just a bit too salty, though I can understand why the salt was added in the first place. This recipe made 9 cups, which is just a little too much breakfast for us, as I don't like to eat the same thing every day. I suppose it could be frozen, but I didn't try it. I'm not sure it would be too good to eat as breakfast when it came out, but might be a neat mix-in for pancakes or something.