Aldi is great if you know how to shop there and if you have a decent store in your area. (Some locations are disgusting.) If you're shopping for your elementary kid's lunch and are buying juice boxes, bread, PBJ, chips, lunch meat. fruit snacks, cheese sticks, etc., they are great. They have a good selection of inexpensive nuts and trail mixes. Eggs, butter, and milk have hard-to-beat prices. Frozen products are good, but it is clear they make their money on things like fries and tots, (small portions and relatively higher prices). Frozen veggies are cost competitive, but the portions are small. Rice, beans, tortillas, and cheese, you might as well shop at Walmart in terms of prices. Cereal is the same way, but Walmart wins on price and larger sizes. Aldi pizzas are great. Not much selection, but the prices cannot be beat and they are about the same as cheap deli pizzas anywhere else. Their chocolate cannot be beat in terms of quality and price.
The best recommendation I can give is that when I shop at Aldi for just a handful of things that I need for dinner, I will always spend much less than at Walmart. The only problem is that I still end up shopping at Walmart or on Amazon for some items, mostly cleaning supplies and toiletries.