You can get a bunch of different dark chocolates that have different percentages of cacao in them for an interesting tasting experience. I suggest starting with the lowest percentage of cacao and making your way up to the highest.
Did you know that 100 percent cacao, with no sugar at all, has a taste that is more bitter than coffee and some may compare it to burnt coal? My favorite chocolates are always around the 75 to 78 percent cacao range. With this kind of tasting, you can also pair several wines to match the strength of the cacao in the chocolate.