Vanilla easily.
I love actual chocolate, but I HATE chocolate flavoured stuff. It tastes nothing like chocolate most of the time, and is utterly horrible. Never liked Chocolate Ice Cream, Chocolate Milkshakes, Chocolate Topping - or any other entity that bares the name "Chocolate" without being chocolate, with the sole exception of hot chocolate.
As for chocolate richness... Never enough. So long as it is real chocolate, or made with real chocolate, the chocolate can never be too rich. I love things so rich I can barely eat a mouthful of them because they have some serious flavour to them, and the richer the chocolate the better IMO. Of course if the chocolate tastes like shit I'm not going to enjoy that richness much, but if its good chocolate then the richer the better.