Green & Black's got me started with good chocolates a bit over a decade ago.
I still like an occasional G&B bite, but my recent favorite is Fine & Raw cacao & coconut chunky, made in Brooklyn. One of the very few American-made chocolates I really like.
A second favorite would be generally any 83% or darker. Occasionally I even go for a lower content if there's a good reason - like delicious pieces added of something that matches. Ginger, orange, cranberries, random nuts etc.