Wet food is better for overall health as it contains all the moisture a cats needs which is very important. True, tinned food does little for their teeth (but then dry food doesnt either, contrary to what some pet food manufacturers would have you believe!) Most dry food is also full of carbohydrates, which cats don't need in their diet and dry food is dehydrating by its very nature. Go Cat is mainly cereals, veggies - hardly any meat in it at all, so not ideal, Whiskas products arent brilliant in terms of meat content and some do contain cereals (although Whiskas Supermeat in tins, doesnt). Have a look at this site for really good info about why dry food isnt best for cats (written by vet Lisa Pierson)
http://catinfo.org/ . A good way to help keep teeth clean is by giving cubes of raw or cooked meat, or raw chicken wings.
There are quite a few good quality high meat content/no carb i.e. cereals, wet foods, for instance Hi Life Real Meat (poultry or fish), Nature's Menu, Applaws (does contain a small percentage of rice and isnt complete), Bozita. Good quality dry with low carb + high meat include Applaws and Orijen.
Tuna is ok to give, but only as an occasional treat (she might like some of the Applaws tins as they have fishy varieties)
Personally, I feed my cats twice a day with a mainly raw diet, along with occasional Hi Life or Applaws, with a handfull of dry food at bedtime. And, yes mine are interested in my own food too LOL! There's quite a few human foods that are a no no for cats, including onions, garlic, tomatoes, chocolate, processed meats (too much salt) and I'm sure others will think of more things I havent mentioned.