Recently I've just been doing cento crushed tomatoes (canned). You need to season it (at least salt and pepper dear God) and ideally add some onion and garlic, maybe mushrooms or meat. But I'm also the type to add additional seasoning and ingredients to "finished" store bought sauces anyway, so maybe you're looking for something more complete
Okay, forget the meat and mushrooms, I tried to imply that those were optional. Let's say you use that jarred minced garlic (I don't like the stuff personally, but it's easy). You're going to be letting the sauce simmer anyway I hope, so while you wait you season to taste. Yes that's one or two minutes that you could've scrolled on Lemmy while you wait for your sauce to heat up, though I guess if you don't like cooking you might be content mixing a ladle of cold sauce with the still warm noodles.
Ya I think "more complete" would be accurate, but also low/no sugar content. I always open up good looking jars, and then upon tasting them, they are super sweet. Gimme that acid!