I tend to buy a lot of store brands and have found them to be mostly good. However, one thing I have noticed on occasion is that sometimes the store brand of a product has more crummy ingredients like partially hydrogenated oils or artificial additives. Triscuit-type crackers are the first example that comes to mind; I will not buy the Shaw's brand because they contain trans fat while the brand-name version (or Trader Joe's brand, for that matter) does not. Yogurt is another example (unnecessary additives, not trans fat) other than, again, Trader Joe's. Other than cases like that, I'm not picky and so tend to buy the cheaper store brands.