Cook the rigatoni noodles until al dente or according to package directions. Drain and set aside. Brown the sausage, ground beef and 2 chopped onions. When meat is cooked thoroughly, add chopped cloves of garlic. Cook until garlic is tender. Drain fat from mixture. Add all remaining ingredients except for the parmesan cheese. Put in to crock pot and cover. Cook on low 4-6 hours. Sprinkle with parmesan cheese and serve. You can also top with shredded mozzarella cheese.