Re: Best brand to buy from grocery store?
Other members are much more knowledgeable than me, but at the grocery store, your best bet will probably be Iams. I think PetsMart will give you better choices for healthier cat foods though I think the better/best cat foods are probably going to be found at the little Mom/Pop specialty stores. I have a feed store (horses and other livestock) that carries the Innova and Evo products and that is what I am feeding now, with the occasional treat of "kitty-crack", which is what I call the grocery store brands of dry Fancy Feast, Purina or Meow Mix. Most of the grocery store brands of cat food would be comparable to our human 'fast food' types of food; qucik, easy, delicious...but not very healthy when eaten exclusively.
You may be able to do a Forum Search for threads/posts about the better cat foods. In order of best and healthiest for cats, I think it would fall: raw diet with carefully balanced nutrients, vitamins & minerals, premium canned food (not the grocery store canned food), premium dry food and falling very much lower on the scale would be the more common commercial cat foods.