By far and away if I had to choose the one thing in my home that has saved me the most money, I would say my chest freezers. They allow me to buy in bulk and keep a long term storage of things that aren't canned or dry goods. They are mandatory in my life now, but keeping them organized can be a serious challenge. Taking a little bit of time every couple of months to organize, clean out, and reasses what we have and what we need can be a real help in meal planning and making sure I'm working through everything we have.