Every year in February the Whole Dog Journal puts out it's list of the best dog foods. They are not ranked, because there is not one best food because all dogs are different. They either make the list or don't. The WDJ is like the consumer reports for dogs - they do not take any ads, etc. I consider that list to be the best, most unbiased list of good dog foods. But, you can figure out a good food just based on the ingredients! Chicken and Chicken Meal, Lamb and Lamb meal are best. Chicken by-products or meat/animal by products are the worst. Preservatives are bad. Corn is bad. Here's a good explation of ingredients:
http://www.sniksnak.com/ac/petfooddefinitions.html
It's hard to find the WDJ list because you have to pay for either a subscription to their magazine or the website. Just like Consumer Reports.
http://www.whole-dog-journal.com/ Some of the easier to find brands on the list are:
Canidae
Innova
California Natural
Chicken Soup
Wellness
Natural Balance (only the Ultra Premium formula)
Every dog is different, but we tried Innova and Loki didn't like it. Natural Balance was good for his sensitive digestive system and he was on that for a long time. I just switched him to Canidae and we're happy with it.
I hope this helps!