ALDI saves us a lot of money each month. We like nearly everything we've tried (except for the pasta). The store can offer inexpensive options for a few reasons. The selection is limited to ALDI's store brand (with the occasional national brand on special) so the store's footprint and staff is quite small. You bag your own groceries in reusable bags. A quarter rents a cart. Returning it gets the quarter back. So European!
I buy all of our staple foods at ALDI (flour, sugar, basic spices) as well as dairy, eggs, produce, bread, and frozen meats (ground beef and whole chickens). Depending on what we need, I'll also get treats (ice cream, frozen fruit bars) and produce there. ALDI doesn't carry certain specialty products, so I can't just skip out on a regular grocery store completely.
Do you shop at ALDI? How do you save a few pennies on groceries?