Champagne is the worldwide drink of celebration, and while it's terrific on its own, a good cocktail can dress it up. If you like lemon or gin, try a French 75. If you're having brunch and want some Vitamin C, why not try a Mimosa?
Tip: The secret to making a great cocktail is all in the ice. Use filtered water so the ice doesn't impart any off flavors to the drink, and go big. The larger the ice chunk, the less you'll water down your drink.