You want fat on a duck, which is why they are at their prime just before they begin their winter migration and at its end, when they're plumped up again. But you don't want so much of it that the bird tastes of nothing but fat. The age of a duck, as with any fowl, is crucial to its preparation. If the bird's got plenty of pinfeathers, it's a young, more succulent duck. The plumage of older birds tends to be more colorful.
Domestic duck tends to be cooked till the skin is crispy and the meat gray and tasteless.
French chefs tend to cook duck bloody rare. Somewhere in between those extremes is the happy medium, where the blood exudes its own flavor, there is still a delectable rind of fat under the skin, and the meat has a wonderfully velvety texture. Cloyingly sweet sauces mask flavor, though several classic recipes do call for orange or cherry glazes. Here's a simple roast wild duck recipe I think works extremely well. Season with salt and pepper.