Diana,
I like the Endangered Species Dark Chocolate with Forest Mint. Since I have totally eliminated sugar from my diet, it tastes great to me. The mint flavor kind of "hides" the bitterness of the dark chocolate.
Endangered-Species-Rainforest-Natural-Chocolate. I can find them in Kroger's, if you have those grocery stores near you. I am pretty sure health food stores would carry them, too.
Also as a plus quoted from the manufacturer:"Endangered Species Chocolate donates ten percent of net profits annually to protect wildlife and habitats. With over $1.2 million donated to date, premium chocolate adds up to big support for at-risk species."
You probably can find a Valentine-y container at a craft store like Michaels to put the bars in.