Grand Marnier-or "GrandMa," as some cocktail geeks gleefully shorthand it-remains one of the classics. Although it's Cognac-based, it's a versatile match for other spirits, too. The liqueur is extremely aromatic, with lots of sweet and bitter orange notes exploding out of the glass. Look for a warm, honeyed flavor and a nice burst of orange peel and spicy cinnamon and ginger on the long finish.