I am moving out earlier than expected and therefore my room will be available from early-mid december. (Possibly the 6th or 7th).
The room is in a large 100m2+ appartment that is shared with the owner, a french lady in the early 60s. The toilet, bath, and kitchen are shared a long with a living room that neither the owner nor I use much. The room itself is probably 4x4m, there's a nice bed, small table and two large cupboards for your use. There's a TV in kitchen that you can use.
I have paid about 550€ a month including electricity, gaz, and internet Protected content all included basically).
The location is in Courbevoie which is in Zone 3 just north of La Defense. There's either a 5 minute walk to the Becon Les Bruyeres station (linked to St. Lazare in Paris, La Defense or Versailles) or a 10 minute walk to the metro station Pont de Levallois at the end of line 3 which brings you downtown in about 15 minutes (serving places like Opera or Sebastopol). All relevant shops are between the apartment and the Becon train station.
If you're interested, drop me a message/answer with some contact details and I'll either give you the owners info or forward you to her.