Let’s be honest; there’s no such thing, it’s impossible. This is because how nutritious a food is will be entirely dependent on your dog’s breed, age and particular dietary requirements.
Every dog is different, and you need to find the right balance for your dog. When it comes to their food, this is all that matters, and no food can guarantee this for every single dog. You have to find what works best for you.
To get a better idea of what you should look for, however, I would strongly recommend speaking to your vet. They’ll be able to tell you what to look for and what your dog most requires. From there it’s simply about what your dog enjoys and what you can afford.