I eat a huge breakfast normally, like 400 to 500 calories. That's because I'm eating 1500-2000 calories a day, and tend to spread them out. But I also need to get in protein or I die! (Well, a bit melodramatic, but I get hungry.) Here are some of my favorites:
Homemade "Egg McMuffin" - 1 light english muffin, some light margarine, 1-2 eggs worth of EggBeaters, Morning Star soy sausage patty, 2% Kraft cheese slice. About 350 calories, depending on how much you use. I usually add some fruit. I have this thing down to a science, I can make it in about 5 minutes of frantic kitchen maneuverings.
Oatmeal, fruit, and cheese: The oatmeal tends to fill me up, the fruit is healthy, and the cheese adds some protein and needed calcium for me. I mix it up between types of oatmeal, types of fruit, and whether I'm eating lowfat or full fat cheese, it's just whatever I have. Tends to be about 320 calories, and then I have something as a midmorning snack. Or sometimes a second bowl of oatmeal, if I'm feeling starved.
Cereal with fruit and 2% milk and a soy sausage patty: I forget what this adds up to calorie-wise, but I usually just go with raisin bran (sometimes Special K and some cut up banana) and toss in a soy sausage patty for protein.
I also do 'breakfast on the run' sometimes. Those are weird mornings, when I just want to eat 'junk food'. My favorite, favorite, favorite to pick up in those moods is the McDonald's fruit and yogurt parfait with granola, it's only a dollar (less than some spend on coffee!) and like 160 or 180 calories, I forget which. But I need to eat something protein along with it, like some cheese or a Luna bar. Or I'll do a bagel and light cream cheese, I just have to be careful because most bagels are humongous.
I've also been known to eat 'dinner food' for breakfast. Just, leftovers from the night before, or a frozen entree. I figure if I eat breakfast for dinner sometime, I can eat dinner for breakfast sometime.