I agree that the potatoes get a little mushy, but that's the only vegetable I've had a problem with when freezing soups. Mashed potatoes freeze fine, though.
Any pasta or rice based casserole freezes well, as do cabbage rolls, stuffed peppers, pot pies, fillings for tacos, enchiladas and such, cooked meats in gravy.
When you find ground beef on sale, you can make it up into meat loaves and hamburger patties and freeze. Then all you have to do is thaw and cook.
If you buy some food trays with compartments, you can make individual meals from leftovers, label and put in the freezer to use as needed.