Make your own. I know alot of people buy meatballs from the freezer section, but I can't do it. Here is what I do:
In a mixing bowl, mush together 1 lb ground beef or turkey and 1 lb of italian sausage, 2 eggs, salt & pepper, oregano & basil & garlic, and breadcrumbs, crackers, or something similar(not sure on the amounts, I add stuff until it looks good).
Form meatballs and place in baking dish. Bake at 350 for 20 minutes or until cooked through(taste one, just because they smell so good).
After cooling a bit, place onto a baking sheet in the freezer. When frozen, place in freezer bags(I portion them out, enough in each bag for 1 meal). When ready to cook, I just toss them into a glass dish in sauce, microwave until heated through. You can thaw them for faster reheating, if you like. Serve with pasta or on deli rolls for a homemade meatball sub.