We feed our dogs a Canadian-made dry dog food called Orijen, which runs about $80 a bag. They use only natural, free-range ingredients, no preservatives and include a ton of vitamins - sometimes I think that the dogs eat better than us!
Luckily, because the food is so rich and high in nutrients, they eat about half as much as they do any other food (and we've never fed low-grade food by any means), so the cost isn't quite as steep as it sounds.
We used to feed my dogs dry food. Now that one of my dogs is older and losing teeth, we turn her dry food into wet food. Wet food can be really expensive! Of course this made my other dog jealous because for some reason she liked the new, softer food better, so now she gets softened dry dog food as well.
We just adopted a puppy so she eats 3 times a day. The first two meals are usually just dry food. The final meal is often times a mix of wet food and dry food. Like Surreptitious, my dog eats the fancy schmancy natural dog food.
We feed him dry prescription food. Wet food might taste better - but it sticks to their back teeth - there's a lesser chance to have plaque accumulation on their teeth when feeding them dry food. But no matter what food he eats, I brush his teeth every night.