We feed ours Natural Balance Limited Ingredients. Readily available, good quality, not too much filler. We chose it because we didn't have to change up the dog food from puppy to adult and it's stuck around. It's also cheaper than a lot of the other "fancy" dog food.
We've been using Natural Balance Lamb and Rice and just recently switched to Diamond Lamb and Rice because it's way cheaper and as good for him health wise. Just make sure it's grain free! Also, we've found that he's the least gassy with lamb vs. other meat and fish.