The One and Only Dog Food Brand I Recommend...

is Canidae. Here are the ingredients in the Canidae All Life Stages food:

Chicken meal, turkey meal, lamb meal, brown rice, white rice, rice bran, peas, potatoes, oatmeal, cracked pearled barley, chicken fat (preserved with mixed tocopherols), millet, tomato pomace, natural flavor, flaxseed meal, ocean fish meal, choline chloride, sun cured alfalfa meal, inulin (from chicory root), lecithin, sage extract, cranberries, beta carotene, rosemary extract, sunflower oil, yucca schidigera extract, dried enterococcus faecium, dried lactobacillus acidophilus fermentation product, dried aspergillus oryzae fermentation extract, dried bacillus subtilis fermentation extract, saccharomyces cerevisiae fermentation solubles, vitamin E supplement, iron proteinate, zinc proteinate, copper proteinate, ferrous sulfate, zinc sulfate, copper sulfate, potassium iodide, thiamine mononitrate, manganese proteinate, manganous oxide, ascorbic acid, vitamin A supplement, biotin, calcium pantothenate, manganese sulfate, sodium selenite, pyridoxine hydrochloride (vitamin B6), vitamin B12 supplement, riboflavin, vitamin D supplement, folic acid, cobalt proteinate, organic selenium, papaya, pineapple.

As you may(and should) have noticed, there are no by-products, and the first 3 ingredients are meat, rather than grain fillers that are inedible. After this meat is the grains, rice which dogs can absorb carbohydrates from. As compared to Iams ProActive Health Adult Chunks:

Chicken, Corn Meal, Ground Whole Grain Sorghum, Chicken By-Product Meal, Chicken Fat (preserved with mixed Tocopherols, a source of Vitamin E), Dried Beet Pulp, Chicken Meal, Chicken Flavor, Potassium Chloride, Dried Egg Product, Brewers Dried Yeast, Salt, Flax Meal, Fish Oil (preserved with mixed Tocopherols, a source of Vitamin E), Caramel(why does a dog need this?), Choline Chloride, Minerals (Ferrous Sulfate, Zinc Oxide, Manganese Sulfate, Copper Sulfate, Manganous Oxide, Potassium Iodide, Cobalt Carbonate), Calcium Carbonate, Vitamins (Vitamin E Supplement, Ascorbic Acid, Vitamin A Acetate, Calcium Pantothenate, Biotin, Thiamine Mononitrate (source of vitamin B1), Vitamin B12 Supplement, Niacin, Riboflavin Supplement (source of vitamin B2), Inositol, Pyridoxine Hydrochloride (source of vitamin B6), Vitamin D3 Supplement, Folic Acid), DL-Methionine, Rosemary Extract.

Sheesh. Such a premium dog food.
Also, a 50 lb. dog only has to be fed 2 cups of Canidae- but 2-1/2 cups of Iams. You feed less, get less poop, more nutrients, a healthier dog, and a heavier wallet in the long run. What more can you ask for?