I'm in agreement that the most important thing is that a dog gets fed. I think there are definitely some foods that are more and less healthy than others but everyone needs to make their choice on what they feel is best and be comfortable with that. Mine do well on Royal Canin Natural Blend, and it has been an affordable high grade food with meat as the first ingredient. When I was younger and we had the collies, Mom got Diamond, which was what was affordable for us and the collies did well on it.

One thing my vet has always told me though is that "light" and "senior" foods are not so great. He said they degrade the quality of the food and add more filler to make it "light" and it isn't really healthy. He believes seniors or overweight dogs (not caused by medical conditions of course) should just have portions of regular food carefully monitored and reduced as needed, and of course exercise is always best too.