Interesting question—but what type of dish are you looking for when you say "the best recipe"? Are you looking for main dishes? Side dishes? Desserts? If you haven't tried a "traditional" Christmas dinner (with the turkey/roast beef/ham, mashed potatoes, and all the fixin's) you really must! Check out this website for specific recipes related to this: www.bhg.com/holidays/christmas/recipes/.
On the other hand, I really like to try new things for Christmas dinner. We always go traditional on Thanksgiving, but our Christmas menu is unique and fun. For example, we've done themes for Mexican Christmas, Fondue Dinner, Spring Roll Party, Pasties, Paella, Appetizers and Wine, and more. Every year it's something new and interesting (which reminds me, I have to plan something for this year!). For more ideas yet, check out Our Best Holiday Menus , available on newstands now or go to www.bhg.com/holidays for some cool ideas.