there's nothing wrong with cereal. Of course, some are better than others...but you're probably not eating cocoa puffs or cookie crisp before going to the gym!
i alternate breakfasts throughout the week. Some days I have a high fiber/whole grain cereal like fiber one or all bran. I usually have some kind of fruit with the cereal. Cereals that have almonds in them are good because they're a great source of protein as well.
Some other suggestions:
whole grain english muffin with a 1tbsp peanut butter with a low fat yogurt.
i egg and i slice of low fat cheese on 2 slices of whole wheat toast, you can add a slice of ham, veggie or turkey sausage or turkey bacon.
(one of my favorites) 2 egg omelet (real eggs or egg substitute) filled with low fat shredded cheese and veggies (tomato, spinach, pepper, onion, mushroom, etc)
2 whole grain frozen waffles with 1/4 cup sugar free syrup with a slice of ham, turkey/veggie sausage, or turkey bacon