Mark Sisson has covered the breakfast topic quite well from the paleo (actually, for Mark, Primal) end. Another great blog, Feel Good Eating, also covers the topic of what paleo oriented eaters have for meals. From the CR end, April Smith is famous for her egg whites/flax oil combo.
I know this sounds silly, but it was a revelation for me that you could eat non breakfast foods at breakfast. At first when I began eating more healthfully, I was eating rolled oats, usually with sliced banana or pumpkin and a ton of Splenda. But I realized that sort of breakfast supplied a huge dose of carbs, very little protein or good fat, and left me starving two hours later. When I switched to poached eggs for their better nutritional profile, I began to wean myself off the sweet stuff for breakfast. In a couple of months, I was experimenting with all kinds of non breakfast foods: leftover salmon with broccoli, chicken breast with a V8 juice chaser. This morning I had an organic chicken sausage with a drizzle of mustard and steamed cauliflower with lemon olive oil.
Of course, there is the time issue. Opening a cereal box is easy, right? But steamed veggies? Well, I timed my breakfast this morning. I took out my chicken sausage, sliced it up in rounds, threw it in a bowl, and nuked it for thirty seconds. I had chopped the cauliflower the night before, so I threw that in another bowl with a bit of water, covered it, and nuked it for 3:30. I drained the cauliflower, drizzled the olive oil on top, and voila. 4 minutes of cooking time, maybe a minute of prep, and I had a nice, nutritionally well rounded breakfast. Often I can't be bothered to warm the meat up, so I'll just eat cold leftovers--even faster.
My darling SO also loves his eggs--for him, breakfast is always a couple of slices of uncured bacon and a nice scramble. Once I have cooked the bacon (6-8 min) I drain off most of the grease, and pour a couple of eggs beaten with a bit of cheese, and gently cook them over low heat (3 min). Of course, we both have the advantages of having high thresholds for boredom and liking leftovers :)