I have a problem with jarred spaghetti sauce... too much sugar! Sometimes the sauce ends up tasting more like a dessert topping! I understand that the sugar cuts the acidity of the tomatoes, but I really think they are overdoing it. I have found that it is simply easier to make my own. This is a very flexible recipe - it can be easily changed to match your personal tastes or to use up whatever is languishing in the fridge. And best of all, you can easily make this in the time the pasta is cooking!
Heat olive oil in a large, deep skillet.
Add crushed garlic to your liking (I love garlic so I usually use 4-5 cloves) along with chopped veggies such as sweet or green bell peppers, chopped celery, or shredded carrots. (Most veggies will work here, so be brave if you have something that needs to be used up - I've used zucchini and was tempted to add beets the last time I made it. If you don't think your kids will go for it, just shred it and it pretty much disappears into the sauce.) You can also add crushed red pepper flakes here if you like a little kick to your sauce. Saute for a few minutes until the veggies begin to soften.
Add one 28-oz can crushed tomatoes (I like the Great Value brand from Walmart - no skins and not too many big chunks) and ~one teaspoon each of basil and oregano (I don't usually measure these - just taste as you go along, but remember that dried herbs need to simmer for a few minutes to release their flavor), one teaspoon of sugar (if you added carrots with the veggies, you probably won't need to add any sugar - taste first!), and salt and pepper to taste.
Just before serving mix in 1-2 cups finely chopped spinach (I run it through the food processor) to give a great pop of color to the sauce - and extra nutrition too!