Canidae has some very conflicting reviews. Do a search here for links to complaints on their formula. Diamond I think is a 1 star food. Chicken Soup is ok, though Blue Buffalo is has a higher rating.
The site Caney suggested will give you all you need to know. Start with researching the ones suggested to you, then go to the 4-6 star section and find one available to you. The higher the rating the better of course. Some are minimally more expensive than most. Some are outragiously expensive in this economy. Do the best you can with what you can afford.
LISA ~ Lily LaRue - 4/07 boxer; Buster McDoogle - adptd 6/07 Vizsla/Besenji mix; Annabella Kanicki - 5/08-7/09 staffy; Mr. Smiley - 4/10 Boxer/pibble mix; Fozzy Bear - 5/10 Red Heeler/pibble mix