What are the names of the “store brands” at the grocery where you shop? Do you buy the store brands often? Of which items do you have a preference for a nationally branded item over the store's own brand?
The groceries in Kansas City stock two different off-brand brands. Always $ave and Best Choice. I buy either of these brands frequently for staple items like flour, beans, baking soda, baking powder, raisins, oatmeal, sugar, and salt.
I don't use Always Save or Best Choice for coffee (seriously, man, their coffee is gross–nasty coffee is not a good savings). Ditto their cleaning products, except for bleach and vinegar. You can't fuck up bleach or vinegar, but you can make really stank laundry detergent and too-watery dish soap.
When I buy cereal, I buy the Malt-O-Meal bagged cereal, goofy names and all. It's cheap and not appreciably different from the boxed kind. Plus, you can't get puffed rice anywhere else, as far as I know.
It seems like there are regional brands of dairy products. Where I grew up, Lucerne was the big one. Here in Kansas City, it's Belfonte (my favorite yogurt comes from Belfonte) and Roberts, with a cheese brand called Hautly.
Where I grew up, the off-brand/store-brand was “Our Family,” and they filled a pretty similar niche as Always Save and Best Choice. Cheaper basic items, mostly. Dry goods, canned goods, a limited selection of cleaning products.