In a skillet over medium heat, brown the ground beef with the chopped onion and minced garlic until the meat is no longer pink. Drain excess fat.
In a large Crock-Pot, combine the browned meat mixture with crushed tomatoes, tomato sauce, tomato paste, dried basil, dried oregano, sugar, salt, and pepper. Stir well to combine.
Add the water to the Crock-Pot and stir again.
Break the spaghetti in half and add it to the sauce mixture, ensuring it is submerged in the sauce.
Cover and cook on low for 6-8 hours or on high for 3-4 hours, stirring occasionally if possible.
Once the spaghetti is cooked, serve hot with grated Parmesan cheese and fresh basil if desired.