Wet food comes in cans, trays and pouches, and this page has all three. Before anything else, check whether the pack says complete or complementary. Complete means it's a full diet on its own. Complementary means it's designed to go alongside something else, usually dry food, and shouldn't be the only thing your dog eats.
Cans, trays or pouches
It's mostly about your dog's size and your fridge. A tray or a pouch is one meal, so nothing gets opened and half-used. A can is cheaper per kilo but once it's open it needs covering and refrigerating, and it wants using within a couple of days. For a small dog, a large can is usually false economy.
What wet food actually costs
Wet food is roughly three-quarters water. That makes the price per kilo look reasonable and the price per meal look less so, because you need a lot more of it to deliver the same calories as kibble.
For a small dog, feeding wet only is perfectly affordable. For a big one it gets expensive quickly, which is why most people with large dogs end up feeding dry food with some wet mixed through it rather than wet alone.
If you mix wet and dry
Count both. This is the most common way dogs quietly gain weight: a full measure of kibble plus half a tray on top, twice a day. Work out the daily total from each pack's guide and split it between the two, rather than adding one to the other.
Wet food and teeth
You'll hear that dry food cleans teeth and wet food rots them. It isn't that simple. Ordinary kibble does very little for dental health either way. If you're worried about your dog's teeth, brushing and a vet check will do far more than the choice between wet and dry.
Prescription diets
A good number of the products here are veterinary diets for specific diagnosed conditions. If your vet has named one, buy that exact product. If they haven't, these aren't a general upgrade and some are actively unsuitable for a healthy dog. The veterinary dog food page has them together.
When to bother at all
Wet food is worth reaching for if your dog is a poor drinker, off their food, elderly, dental-sore, or you just want to make dinner more interesting. If your dog eats well and looks well on dry alone, there's no health reason to add it.