I have three cats and I only feed mine dry cat food. I used to feed a combo of both until my vet told me that canned food is horrible for their teeth. I did notice a lot less plaque after I stopped giving them canned.
The food that I feed them is a human grade quality, very expensive food that has no grains or plant materials in it. I've done an astronomical amount of research on cat and dog food as I lost my Pittie to the 2007 dog food recall.