The best chocolate, surely, is the chocolate you like best? ;-)

Beyond that, I'm a fan of Green & Black, including several of their various flavoured ones. But I'm also fond of Roses / Quality Street / Milk Tray. I suppose my focus is really "Do I like this?" rather than "Is this chocolate?", a question that seems to afflict lawmakers & aficionados. I gather that on the continent, a lot of what we call chocolate e.g. Dairy Milk couldn't be labelled as such (not enough cocoa solids). Doesn't stop me enjoying it!