We do steel cut oatmeal in the crockpot overnight as another person mentioned. We usually add in something just before serving like raisins, dried cranberries (Craisins), brown sugar, milk, etc so the kids can pick how they want it. We also spinkle fresh fruit like blueberries on top when they are in season. I usually add some wheat germ to the oatmeal, too - the kids have no idea it's in there.
Sometimes I make a batch of healthy muffins on the weekends (some whole wheat flour, wheat germ, etc) to eat during the week. They freeze well. I also make pancakes (they are fairly healthy the way I make them) at least one morning on the weekend and whenever I make them, I make double the amount we need and freeze the extra. They are good on school mornings to zap in the microwave.
My kids just eat cereal most mornings, though. It's fairly quick - they can pour it themselves while I'm getting ready (well, the 7 & 4 year old can, other is too young) and eat it all within 10-15 minutes.
Since breakfast is the most important part of the morning routine we make sure the kids have 15-20 minutes for breakfast. If you can't do that you may want to look at your morning routine... we do alot the night before: picking out clothes, packing backpacks and putting by front door next to the shoes, deciding on lunch and mostly packing lunch if bringing (with cold stuff in one pile in the fridge for easy grabbing at last minute), etc. My son wakes up at 7am, out the door to meet the school bus by 7:45am and he usually has time to watch 15-20 minutes of TV (TV is off until all ready for school). My daughters and I leave the house by 8:15 most mornings. We have our 'off' mornings but for the most part they are relaxed and nice.