I particularly like Hotel des Academies et des arts. It's not a budget hotel so if you are looking for something under 100 euros, no need to look at this one. Anyway, 100 euro hotel is almost impossible to find in the French capitale.
Back to the hotel, this one is very nice, well located because between Montparnasse and Saint Germain des Pres, the staff is polite and speaks English, the rooms are artistic.
Let me know what you think.
This tip has the address "15 rue de la Grande Chaumière 75006 Paris, France"