Ideal service temperature ranges from 45-50F (light bodied white and red wines, including sparkling wines) to 60-65F (full bodied red wines).
A practical advice:
Flat, at constant (ideally 55F) temperature with sufficient humidity (50-70%), possibly in a dark space.
Champagne! It is cheerful, enjoyed by everyone I know, and very versatile (it pairs easily with all courses). And there are many, less expensive, sparkling wines produced in the same way and well worth a try, including Crémant de Bourgogne, California sparklings, and Franciacorta.