I highly recommend Leopold's apartment on Mouffetard. The flat itself is clean, very cozy, feels like a home and is fully equipped. Leopold and Colette were away but their friend Rose-Marie has shown us in and around the apartment, answered all our questions and was tremendously amiable.
The location then. It is absolutely fantastic. Moufettard is full of small shops with all kinds of fresh food and wines. All these culinary riches right next door to us gave us a great option of cooking at home (the kitchen has everything one needs for this). There are of course scores of restaurants, brasseries and bistros on Mouffetard so the choice is yours. And a short distance away in the direction of Panteon there are student hangouts, pubs and nightclubs.
Accesibility is beyond any reproach - Place Monge is about five minutes walk, which gives you access to the Rigth bank - the subway takes you directly to Louvre, Opera etc.
Defnintely a great choice.