I voted for Dark (the most popular choice by a wide margin, it seems), but there’s something to be said for adding Milk and White to achieve a balanced diet. :-)
As to Nutty — I tend to agree with the common sentiment that “Nuts just take up space where chocolate ought to be.”
But I’m fond of liqueur chocolates too.1 And here’s one that hasn’t been canvassed yet: Dark chocolate with Chili, a satisfying combination that tastes surprisingly “right.”
1Update: and Rum and Raisin deserves an honourable mention.