There are three types of food for your cat, dry cat food, wet cat food and raw (they catch this sometimes).
What is the best? One of the points that some people make about dry cat food is that cats tend not to drink enough to compensate. If this is the case they don't urinate enough and that can lead to kidney infection. It is good to urinate a lot to flush out bacteria. Cystitis in a cat can result from eating dry food in my opinion as, by the way, can stress. My cat Binnie can get Cystitis as a result of stress. That is why I never leave her alone for more than several hours (comfort zone for her).
That said, dry food is very convenient and cats like it a lot of the time. The obvious answer is to provide a mixed diet by alternating, for example, fish with dry food. If you add some water to the fish (I use frozen fish) before micro-waving then the fish meal has more liquid in it resulting in the cat drinking while eating.
Wet cat food in the UK is coated in jelly which cats like more than the solid bits leading to waste and perhaps less nuitrition. I think dry food is beneficial for the cat's teeth or at least better than wet food in this regard.
Then we have raw. This kind of food may suite wild cat/domestic cat hybrids as the wild in them should make them more suited to the kind of food that their wild ancestors would eat in the wild.
Finally do you provide whole animal raw meat or prepared raw meat. Hell, if it's going to be raw give 'em it whole I say.