Brand Name vs. Store Brand

In my recent efforts to live under a very strict budget (thanks to a minimal income), I have in fact become a "frugalista" (to steal a phrase from Target commercials). What does this mean? This means, I spend as little as possible on groceries as my first step. So, I have switched from some brand name products to the "Great Value" Wal Mart brand on items like cheese, milk, sour cream, and a few other products...but I have come to realize that spending a few extra dimes can be worth it for taste. Examples--goldfish, diet coke, and some cereals. I don't care if I save $5 on some of these items, I can taste the difference and it's worth it to me to spend the extra money.
What do you do to cut some nickels and dimes off of your grocery bills? What items are you willing to spend a little bit more on for good taste?