Most of the heavily advertised dogs foods are actually crap. Purina uses animal by products, corn and other questionable ingredients. They make a food called Beneful that has been linked to many sick dogs and some deaths.
I feed my girls Taste of the Wild. I also really like Earthborn. There are many other good brands out there that are not eukanuba, purina, pedigree and other sub standard dog foods.

I'll be the first to admit I'm a dog food snob.