By servers, for servers. A great section on tipping, including a nice run-down on how celebrities tip and education for the general masses on how to get good service. I don't know that good cooks are any more scarce than good servers, but good cooks will give you great food and good servers great service.
Great food is always great food, but good service is useless without good food.
So I'd have to take the cook. I have to play the devil's advocate here. People will come back to a place with good food if they get great service. They might come back to a place with great food if they only get good service. Yes, servers are a dime a dozen, but great servers are an incredibly rare breed.