At least here in the U.S., high-yield, disease-resistant, good-storage varieties do not always produce good flavor, but these are the kind chosen by commercial growers. Not unlike the tasteless, hard, semi-red things passed off as tomatoes. Problem is, the grower has to produce potatoes (and tomatoes) that are uniform in color, texture and size. They must also have a characteristic known as "shipability"... i.e., they must be tough enough to sustain being transported for days and miles.
Potatoes also are graded into their texture... two main divisions, fluffiness and waxiness. The "fluffier" varieties are grown (like our Idaho Bakers) for eating whereas the waxy types are grown for turning into frozen french fries and products for fast food stores. These rarely have much in the way of flavor, since it's expected they will derive flavor from the deep frying and salt.
Choose new potatoes that are at least 2 to 3 inches in diameter and always cook with the skins on. As some of the posters have suggested, the flavor can be enhanced by adding herbs. Even then, butter, salt and pepper (or other condiments of choice) must be used... Try to buy them loose off the shelf rather than bagged, if available. They're usually fresher and haven't had the "opportunity" to acquire that zesty bagged flavor...