Those foods are all really crappy! I didn't know either until I got Jackson and started researching foods. Beneful is terrible! I made this thread after Jackson ate Beneful....
http://www.yorkietalk.com/forums/yor...-him-sick.html
Nutro has been blamed on the sickness and death of MANY dogs and I personally stay away from it.
I would suggest Wellness, Merrick's, Natural Balance, Innova, Taste of the Wild, etc. Any Pet Valu store is going to sell good food. Petco now has some great foods as well. Certain brands are definitely better than grocery brands (Pedigree, Kibbles n Bits, Beneful, etc) though, if you're looking to keep costs low, Avoderm isn't that bad and you can find it at Petsmart and I believe it's a bit cheaper as well as By Nature.