One thing I must argue against is Science Diet. I respect any vet who's been in the industry for years, as it's hard work, but the companies which produce Science Diet give kickbacks to the vets who sell it. It isn't worth what you pay, not by a long shot, and most longtime cat and dog breeders will tell you the same thing. Holistic foods and other such brands are better, and even though they're expensive compared to the stuff at the supermarket, they still generally feature a lower price tag than Iams, Science Diet, etc.
Innova is fantastic.
EDIT: Felidae, which was mentioned in the post just above mine, is also great.
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