Johnny gets Purina One Grain Free Chicken & Sweet Potato. I mix in about half a can of either Purina Beyond (whatever flavor--beef, chicken, or salmon) or Pro Plan Grain Free (turkey or beef). He doesn't like just plain dry food, I think he has a sensitive mouth and the wet food helps it go down easier.
Wal-mart also has their own grain free called Pure Balance in both dry and wet. I've given him some of the wet flavors, they're okay, but I think they have more fillers and he toots more with them.