Surprised no one has mentioned Angelina's in Paris where the hot chocolate is like drinking a melted world-class chocolate bar. So rich that some cannot finish it - but that just leaves more for me.
We once did a blind taste testing of Swiss, French, Belgian chocolates, and the Belgian were the clear winners in our sample. Still, La Maison du Chocolat is hard to beat. And for value, Leonidas is in the running.