Thank you so much Monika, we had a fantastic time in your Chatillon apartment. It is perfect for 1-2 people. We stayed a whole month, and to be honest, we had so much fun in the immediate vicinity, that we only went into the Paris city centre sights 1-2 times per week! The surrounding villages have so much to offer in terms of food, supermarkets, markets and just wandering around and finding local walks and historical buildings, that it was a pleasure to explore the suburbs. The house was well equipped with everything we needed and beautifully decorated, obviously done with much love and care. We found the local shopkeepers and waitstaff friendly and always happy to assist in English, contrary to believe. We had a blast.
Tip 1: Although initially the RER B feels like a long train ride, you get used to it quite quickly, and it's the most cost effective way to get into the city (Eur2.50 if you walk 15 minutes to the station). This takes you straight to Notre Dame. Alternatively, for only Eur2.00, you can take trams+bus combinations into the city for up to 90 minutes.
Tip 2: Within a 10 minute walk from the house, you can see the sparkling Eiffel tower (from nightfall every hour, on the hour for 5 minutes) - just walk to the Bridge above the T6 tram stop called Parc André-Malraux- and enjoy the view :)
Tip 3: We participated in some lovely French culinary classes - have a look online, it really cements the visit.