This is my mother's Traditional Meat Sauce recipe, which she learned to make from her grandmother!
The ingredients for the sauce are pretty simple, so it's important that they're good quality. Choose canned tomato products with fresh, bright flavor - look for tomatoes from Italy or California. Choose sausage that you like the flavor of when it's served by itself.
Sometimes I use a combination of hot and sweet sausages, especially if I'm making a double batch of sauce.
You can definitely use different ground meats, or finely chopped prosciutto or mortadella, or add in some leftover cooked beef or pork - that would be a very Italian-making-Sunday-sauce move. My mother (and I) often add in a shallot if we have one, and substitute dried herbs for the fresh ones if we need to.
Homemade spaghetti sauce and meat sauce are the same thing. That's because most Italian families have one go-to meat sauce recipe, and one Marinara-style recipe, which has no meat.