I have fed Wellness Core, Blue Buffalo Blue Wilderness, Solid Gold Wolf King and my dogs are currently on Taste of the Wild.
I have had good results with them all. I think my favorite was the Wellness Core though, I would love to feed that to my dogs but right now it's just too expensive for me.
Sinister ~ 5 yr old black male GSD 3.11.09
Draco ~ 9 mth old male Dalmatian 6.30.13