I know you weren't asking me Chico but I doubt Gia eats Spaghetti

Regular Pasta Sauce:

Tomato sauce (fresh made or canned)
A big blob of Tomato Paste for thickening and more added flavor.
Oregano both ground and flakes
Basil
Garlic Powder
5 crushed cloves of garlic or finely chopped, minced is fine.
A bay leaf or two thrown in the pot.
A big dash of Cayenne Pepper if its a big pot to add spiciness if you like

For More Extra Flavor:

Thinnly sliced gutted red and/or yellow bell pepper
italian sausage or 95% ground beef cooked on skillet and then throw into pot. Or both if you really wanna get crazy.

Always better the next day or so, so save some leftovers.
If you want exact measurements and stuff for a huge pot of it, let me know. I'll send it to ya.