Ile St. Louis
When in Paris, I like to stay on the Ile St. Louis. Why? Being an island, there's little auto traffic, at night it's a convivial outdoor party on the single main street, there are numerous small (and fairly cheap) hotels, and many restaurants that serve hearty local food without the glitz and the costs that come with it -- and it's within close walking distance to Notre Dame, the Left Bank and much of the stuff you come to Paris for. Ile St. Louis is a quiet neighborhood in the best sense of the term, and should I decide to break down and buy a 'boite' in Paris, it'd be here, on my French island.