DARK 'til death!!!! Currently I'm slowly making my way through the AMEDEI 1 Cru Collection:
This picture isn't great, but it's a beautiful package design of six small boxes, each with six bite-size pieces of 70% cocoa representing different regions: Venezuela, Trinidad, Madagascar, Jamaica, Grenada, and Ecuador. They all taste completely different, and the flavor profiles range from delicate to strong, sour to intense, even floral to earthy. Slowly savor a bite or two after dinner and compare. This would make a SERIOUSLY kick-ass xmas present for the dark-chocolate lover in your life (or yourself). All Amedei chocolate is fabulous, but for the coolness factor I give this box the highest possible recommendation.
Otherwise I like Valrhona, and Scharffen Berger is pretty good too....