a) You will get a different opinion about this topic from everyone you talk with. b) Veterinary nutritionists can't agree on this topic.
But, having said that, I believe there are a number of excellent dog foods available today.
I tend to avoid those with corn or carbohydrates as the first ingredient (although I don't think grains are necessarily bad for most dogs unless they are allergic to them).
I look for AAFCO on the label.
Specific brands which are good include: Wellness, Taste of the Wild, Bil-Jac, Pro-Plan, Solid Gold , Evo, Canidae.
I hope this helps.
I ended up going with the Wellness brand of dog food that was highly recommended by the saleperson at PetSmart as well. What was funny is I was mixing his food still from last time to slowly introduce a new food and now switched to another one. I mixed all three together. All three are different shapes. Well, when I went back into Panzer's feeding area, all of the new food was sitting on the floor. He somehow managed to pick them out and throw them out of his bowl. I think he was undetermined as to whether or not he liked it, but went back and ate them. Could not believe the ingrediants of the Wellness dog food. Very impressed. Thank you for your recommendation.