Switched my 4 from Beneful to grain-free Taste of the Wild High Prairie (your opinions?) and some stinky skin issues have cleared up and my little chubster has lost weight. It's more expensive, but they don't need to eat as much of the grain-free food. I find TOTW itself to be less odiferous than the Beneful kibble. Beneful attracted me with its pretty bag (derp), but it's loaded with corn and I'd been hearing some pretty shady things about Purina's quality, safety, and way of doing business.
TOTW is some good stuff. Diamond Naturals is pretty good too and less expensive.