I start off from the point of thinking what would a cat eat if it was living wild. The answer is meat, with a bit of grass and such like (plus the stomach contents of their prey) thrown in. Then I factor in what I can afford, how easy it is to obtain a food and whether the cat will eat what I want them to eat.
I'm not fond of any dry food and I think there is evidence that a dry food diet is linked to increased UTIs. I can't find the link but I have read it elsewhere. There is anecdotal evidence that a dry food diet may be related to other factors such as kidney disease but that is not proven as far as I know, although if a cat does have kidney disease water intake is very important and cats don't have a strong thirst drive since they would get their water from their food in the wild. So it makes sense to me to establish some wet food in the diet at an early stage.
I feed half wet and half dry (more like 2/3 wet and 1/3 dry really as I throw in a completely wet meal now and again and they have wet with added water at every meal topped with a little dry). For dry food I feed Applaws - a small 400g bag lasts over a month with Mosi, although I'll get through more now that I have 2 cats (currenly Kito is pretty much free fed as he's a kitten and has wet and dry down most of the time). Thrive is another good dry food. I don't like feeding dry foods that contain grains or soy or anything like that but I appreciate the grain free dry foods tend to cost more. You don't need much though - I think it's very easy to over feed dry food because it doesn't look much if you just put down 10g or so. But that's all I feed per meal as there is wet food too.
For wet food, I feed Mosi a variety of grain free food from zooplus. Check out the prices - there are some cheaper ones (Smilla I think is very reasonably priced) and they are often on offer which helps with the cost. I like Happy Kitty Company too (Mosi likes the Macs from there plus they put a free toy mouse in with every order
). I've started buying larger tins now and freezing half as it's cheaper that way and is fine frozen - Mosi will eat it when it's defrosted without any problems. I buy the Bozita tins from zooplus - the 400g tins work out good value. Remember that you tend to need less food when it is all meat than when you food something containing cereals. Seems to fill them up more. There are a few supermarket ones that are grain free - Butchers is competitively prices and is grain free. Some of the Sheba ones are grain free too and Tesco own make pate is grain free. I feed Thrive, Applaws etc wet as treats since they are expensive and most are complementary. Kito apparently likes fresh fish and used to have a weekly treat of coley so I may have to continue that practice! I've started feeding Mosi prepared raw lately and it's going down ok but I don't think he'd go for it every meal (I am feeding natures menu and natural instinct).
That's the grain free which, imo, is ideal. However I know it's not as easy as that and some cats will refuse to eat them, will get upset stomach with some of these foods (I did read somewhere that's to do with different intestinal flora needed to digest the food and cats unused to grain free foods may initially have problems due it being too "rich" - I hesitate to use the word rich when talking about cat food because referring to meat as too rich for an obligate carnivore seems a bit daft! But you know what I mean), or it may just be an affordability issue. I appreciate the latter and that's the reason I feed any dry at all - to help keep costs down. I am an avid label checker and always look to see whether there is any cereals, grains, soy or sugar and try to avoid those if possible. Mosi does best without any grains. That may be because it's what his body is used to as I've fed him that way since he was a kitten. Jaffa, however, was a felix addict and lived to 17 years old without major health problems until the end (kidney disease and high blood pressure). He did eat a fair amount of grain free food during his middle years but he started off with Felix/Whiskas and in his last few years ate the senior versions and eventually renal food.
So not trying to lecture or make anyone feel bad for feeding food containing cereals but I think it's so easy to just pick stuff up off the supermarket without thinking much about it. My own ethos is to start off with what is an ideal diet for a hypothetical cat with no health problems then work back from there. Once you've made a decision and are happy with it don't let anyone make you feel bad for feeding whatever you feed. Knowledge is power.
