It's way cool to find a store that's smaller than a grocery store but it carries everything you would practically want when vacationing. One of my first stops upon arrival is to stock up on beverages, snacks and water. This prevents the mad dash to the local vending machine or bar in the hotel to choose whatever is available.
ABC is humongous! You name it, they have it. It will cost you a little more than most grocery stores but it much more convenient.