Stewed cherry tomatoes with a bit of salt, garlic, thyme, oregano, basil, rosemary, parsley, marjoram (and whatever else you might like)... grind some into a paste, add a bit of water, or milk... (maybe some ghee) a little bit of vinegar (I like Greek pepper vinegar) ... then Carmelize some peppers and some onion and some more garlic with the uncrushed tomatoes... throw those into the simmering sauce.
It's amazing.
As far as pre made stuff... idk. Sometimes Bertolli is alright.