The life of many a party, sparkling wines are seen as an indispensible celebratory ingredient. In recent years, however, the French original, Champagne, has become dauntingly expensive. Enter the US alternative. At the top end of the quality spectrum, US bubbly has become good enough to compete with mass-market Champagne, and often at a fraction of the price. US sparklers tend to be fruitier in flavor and feature less of the complex yeasty notes that belie a quality Champagne. The very best producers offer wines in the $20 range and even less, making them exceptional values.