Cacolac
I love chocolate milk, and French brand Cacolac is king. Out of the brown bottles or vibrant cans, the drink is the perfect blend of sweet milk and real cocoa.
Bizarrely, even though it's been around for quite a while, many French people I've spoken to have never even heard of it. Perhaps because it's quite hard to find in Paris, but it seems to be readily available in supermarkets in Southern France. Search it out if you can, or check out your local Francophile outlet, like the Belle Epoque Patisserie on Newington Green, North London.
