I’m passing through Paris soon. I love chocolate and have a few spots I always visit. My favorite is Edwart chocolatier. Patrick Roger can also be nice. And for treats I know good ones at Pierre Hermès Michalak and Dalloayau (the eclairs) Gerard Mulot and...
Not a broad selection, but each piece is a work of art. They don't mess around with pastries, etc.; just chocolate. For the best "rapport qualite prix" it's hard to beat Chocolatier Rive Gauche on the Rue Dauphine near St. Germain.
You should go and visit Denise Acabo - L'étoile d'or... An old lady who is handling her shop since ages, she only sells the best chocolates she likes... I let you google for pictures