Hey! I am renting out my full-of-books place in the middle of the city; a 50 m2 charming studio with all what one would need :) Warm during winter, cool during summer. Although the apartment is situated in the busy area of saint Denis/Montorgueil, your nights are guaranteed to be calm and full of sleep.
You will never run out of coffee and tea! The apartment is literally in the middle of the city: 5 min walk to Marais, 7 min to Notre dame, 15 min walk to Opéra and Republique
the neighborhood is very lively; bars and restaurants all over the place more than anyone can handle; major visiting sites are at walking distance. I, for example never used public transport to visit
Metro line 3, 4, 8, 9 are a stone throw away
not less then 6 bus lines among which night buses pass in the vicinity
Chatelet metro station taking you to both airports serving paris is 7 min walk away