What makes a meatball recipe worth returning to, specifically the sauce or the meatball itself?

There is a question that comes up whenever I think seriously about meatball recipes, and it has to do with where the real work happens. Some recipes are built around the meatball as the central achievement, with careful attention to the ratio of meats, the binders, the aromatics worked into the mix, and the cooking method that produces a crust worth having. Others treat the meatball as a vehicle, something competent and reliable that exists mainly to carry a sauce that does the more interesting work. Both approaches can produce something genuinely worth making again. A slow-simmered sauce with enough complexity can elevate a fairly simple meatball into a complete and satisfying dish. But a meatball with real texture and depth can also make a plain sauce feel like enough. The question is whether those two things can be optimized together or whether a recipe tends to succeed on one axis at the expense of the other. For a list focused on recipes worth making a second time, I think this distinction matters. A recipe that delivers on both fronts is a different kind of achievement than one that gets the sauce right and asks less of the meatball, or vice versa. What has your experience been with the recipes you have found most worth repeating?