In my never-ending quest to lower our food bill, one item that is a great stockpiler is grated cheese. Colby-Jack, mozzarella, cheddar...we use them all. Cheese prices can vary wildly from shopping trip to shopping trip. Thankfully, grated cheese freezes beautifully. Just throw it in the freezer in the bag. When you take it out, it might be a bit clumped. You can bang it in the same way you'd bang a bag of ice to break up the cubes. Most recipes you can use the cheese frozen, as it defrosts very quickly in the individual pieces.
Other foods I like to stockpile when the price is right: pasta, pasta sauce, canned beans, canned tomatoes, canned fruit (though it isn't much of a stockpile if it all gets eaten immediately), olives, and soup.
We have limited freezer space, or I would have an even more full pantry. I think my husband is just as glad that I am reined in by the limited available space.
What foods do you like to stockpile? Do you have any tricks for keeping food fresh longer? I am always keen to learn.