In my area, Canidae was the least expensive premium food so I started with that (Canidae ALS). My girl liked it but her poops were never very "firm". So I switched her to Innova (green bag) and she did very well on it. The cost difference was only a few dollars more per bag than the Canidae.
Every dog is different, and figuring out which food works best for your pup can be very frustrating. You may end up trying several different kinds before finding the one that works best for your girl. There are TONS of threads regarding food, which I'm sure you will find very helpful. Whenever I switched foods I bought a bag of the new food before the old food was gone. I would mix the two different kinds at each feeding (ex. 3/4 cup old brand with 1/4 cup new brand)and gradually increase the amount of new food each day until it was entirely the new food being given. I know some people feel that switching between premium foods isn't a problem and don't bother making the switch gradually, but I always felt better making the switch gradually over a week or so.
Best of luck to you
