My Mom always made meatloaf this way:
1 lb chopped meat
1 can Campbell's chicken with rice soup
1 onion, chopped small
garlic powder
pepper
1 small can plain tomato sauce (like Contadina or Hunts)
Mix meat, soup and onion together in a mixing bowl. Drop it into a glass baking dish and shape it with a fork into a long loaf about 2 inches thick, making sure to press the sides together. It should be very moist. (make sure you don't go over the 1 lb of meat or you will need more soup) Sprinkle with garlic powder and pepper. Pour can of tomato sauce on top and cover with aluminum foil. Bake at 350 for about 45 minutes.
Now that I am an adult, I have never seen anyone else make this meatloaf. All the other meatloafs I have eaten are heavy and sit like lead in your stomach! This is a light but hearty meal. My kids love it this way.