It's so simple you'll not believe it. You can do this in a crock pot or on the stove, you can use your own meatballs, or the frozen. Ready?
One bottle Chili Sauce, One jar Grape Jelly. Stir on medium heat until the jelly melts, then add the meatballs.
If you use raw meatballs, cook for an hour, or until the meatballs are cooked through (this all depends on the size, obviously).
You can also cook the meatballs on a tray in the oven and then dump them in the warm sauce. Frozen can be used straight from the freezer and go until warm all the way through.
The best part is if you're running low you can whip up a second pot in no time. Watch 'em though, they disappear really fast!