Perhaps you want to begin 2017 with a taste of the sublime. Or maybe you just want to bring a bottle to the party that somebody else won’t be bringing. We have you covered. These five Champagnes, from the most prestigious producers in the region, are rarer and more prized than even the better-known tête de cuvées. Each is available in only a few shops in the United States, so be prepared to expend some effort (and serious money).