Extra Freezer

We rent, and our refrigerator is probably 25 years old or so. The freezer is not large.
With two small children, there's a lot of food that we need to be able to cook on-demand, and we also need some flexibility about when to cook the meals we'd like, which is why we use frozen vegetables more than fresh. Other frozen staples include chicken nuggets, popsicles (in the summer), hamburger patties, pork loin (bought on sale), chicken breasts, pizza, and pasta dishes. Our affection for Costco means we shop less often (which is KEY with little kids!) and we need more room for what we buy.

Enter the extra freezer. It makes it easy to stock up on stuff, and if you have an infant and pump breast-milk, you actually can have room for that storage as well.
I saved money and energy costs by not getting a "frost-free" freezer, but I think if I had it to do over, I'd go with the frost-free. Defrosting the freezer isn't a hassle, but all that frost build-up is annoying on a day-to-day basis.