While to most of us, chocolate is an indulgence and a treat, for others, it's an experience indulgence crafted from the rarest cacao beans, designed to take taste buds to the next level.

Two bars that Hershey's devised for the U.S. military: Ration D, and the tastier (and more enduring) Tropical Chocolate Bar, which soldiers received as late as 1991. Yasu Mizoi When Captain Paul ...