If it's not shop-bought, or in Switzerland (my they do AMAZING hot chocolate), I'd say Galaxy Hot Chocolate, the one you add to milk is REALLY good, or the one you add to hot water if you don't wanna pay the extra money
The milkshake shop in town has just started doing hot chocolate, the Terry's Chocolate Orange one is orgasmic
That sounds friggin AMAZING. May have to go to Shakeaway and get a hot Terry's Chocolate Orange to try and replicate it! I'm also tempted by a Hot Snickers or Ferrero Rocher...
Options, the posher ones, I forgot what they're called. The fudge one.
And for me, there is only one way to make them perfectly. Every time.
The trick is to get yourself one of those tiny whisks that come in hot chocolate gift packs. If you use a spoon it goes lumpy. So get the whisk, and add a tiny dash of milk to the powder, and whisk that beastie up until some lumps are gone. Then add 1/2 the water, whisk up until all the lumps are gone, and add the rest of the water. Marshmallows are completely and utterly necessary.
Put enough milk in a pan to fill a mug along with about a third of a bar of Green and Black's Mayan Gold. Heat it until the chocolate melts and mixes with the milk then boil and drink.