I second Cathy's idea.
You can also check wine magazines like Wine Spectator for recommendations. I also think magazines like Bon Apetit and Gourmet often feature columns on what wines are new, well rated, likely to age well etc.
Before you buy a bottle to cellar this way be sure to buy a bottle to taste, or visit a good wine shop where they offer samples. I've had wine that was rated highly that I didn't actually like the taste of. Wine also can react negatively to changes in temperature and other factors and even fine ones can deteriorate if not stored properly, so get some advice about how to store it.