full disclosure, I used to work for this company, but Earthborn Holistic makes a really affordable natural food. It doesn't really matter what brand you choose, as long as you look at the ingredients. Merrik, Solid Gold, Blue Buffalo, B.G., Halo, InnovaEVO, Wellness, etc. are all very good foods, often times it comes down to your dog's preference or how much you're willing to pay (some of these foods are REALLY pricey). I don't know about the other companies, but Earthborn will refund your money if you have any problems.
Basically, when you read the label on a bag of dog food, you're looking for corn or by-products. Most brands carried in grocery stores (IAMS, puppy chow, and yes Science Diet) all have these. The first ingredient listed should be some kind of protein (it will vary based on the flavor). Also look for root vegetables like yucca and sweet potatoes, and other natural ingredients that you would recognize/also eat as a person (peas, carrots, blueberries, oatmeal, garlic, apples, etc.) The more whole ingredients that you can identify, the better.
The one question people would always ask me when comparing foods is the difference in how the proteins are listed, which actually makes a difference in the food's nutritional value. Some brands will just list "chicken," which means that when they calculate the crude/minimum protein values in the food, it is based on whole chicken that is weighed (in this case, the bones and water contribute to the weight). Some brands list deboned chicken, chicken breast, whole chicken, so on. If you see the words "chicken meal" or "turkey meal," don't make the mistake that this is similar to cornmeal. Protein meals are just dehydrated versions of the meat, so when their percentages are calculated they do not include the weight of the bones/water. Most of the more expensive brands will have some sort of protein meal as the first ingredient. However, if you see "byproduct meal" thats no good. If you decide that you want to cook for your dog, please read about it first- it is not the same as cooking for yourself and many ingredients/methods you would use to make yourself a tasty dish would upset a dog's stomach.
Over the last few years I've worked for a number of different companies and stores, so I'm really familiar with a lot of the brands, what breeds seem to prefer, which is better for allergies, etc., so feel free to PM me if you have any other questions (anybody can PM me if you have any questions! I feel like I don't put my animal feed knowledge to good use now that I don't work in the pet supply industry.) Hope my strange employment history has helped
