There are a small number of things that are good to have at hand at all times. You can get many at local shops.

A contrarian view is that you can also buy these items at better prices at chains that are locally staffed and which may have local investors.

Let's try to keep this list as short as possible, with no more than 3 shops. Feel free to remove one, or all, or flip items, or anything. Be ruthless. Start an edit war.