We were very pleasantly surprised to see The Chocolate Block making an appearance in the CW cabin on our flights either side of Christmas. It seems that we weren't the only people who remarked on it; the cabin crew reported a lot of comments and interest, and the crew on the way back had gone to a shop and bought some to take home and try it for themselves.
I always thought that it was made in relatively small quantities, and had a following that made it something akin to a cult wine, and I never thought that I'd see it on board an aircraft.
Having said that, though, I think it tastes better at sea level.