When I first got Hudson, my breeder was feeding him Royal Canin for Yorkies. She swears by it and has been breeding for a very long time, and is very reputable. I know some people think it's just "ok" but Hudson liked it. After I got him, I wanted to switch him over to Acana which is definitely a more "high end" brand, very good but available only in pet boutiques. I have never seen it at the larger chain pet stores. Whatever you end up doing, just make sure to transition your food very very slowly if you should so choose. I transitioned Hudson very gradually b/c yorkies can have sensitive tummies.
One website that I visited was
Dog Food Analysis - Reviews of kibble. It gives reviews of various dog foods. It was helpful to see how certain brands stack up against others but in the end, every dog is different and like others have said, what works for one, may not work for your fur baby. Good luck!