Depends on your priorities. If you want location and inexpensive, the Phenix on 5 rue General Lanrezac. The phone number is (0)1 43.80.47.63. It is located 2 blocks from the Arc, one block from a Metro stop. I think I paid around $65/night. All the other hotels in the area are around $110-120. The rooms are not good in the summer, no air. The bathrooms are very small. But if you go to Paris and spend a lot of time in your hotel room instead of the city you would want a nicer hotel.
One more idea. Leading Hotels of the World has rates called "Great Affordables," as if anything is their book is affordable! But there are packages that are normally 2-3 nights and usually include a weekend. If you call them they will send the book for "Great Affordables." Discount is approximately 25%