If one can manage to book it (points or otherwise) I strongly recommend the Marriott on the Champs-Elysees in Paris. The location is from the street is almost hidden amongst shops and restaurants but it is situated nearly in the middle of the avenue from the Arc de Triumphe and Concorde Place (which begins the gardens/park leading to Le Louvre). The rooms were very good with both a tub and a shower stall (not to mention the piped in music!). The morning offering of breakfast was an elaborate spread and the staff extremely courteous.
Use of the concierge is recommended as they provided for my wife and I excellent seats to the Lido show the morning of the day we chose to attend. We walked to most locations (some perhaps a distance a bit longer than some would choose to walk but in Paris it just felt great to do so) but the Metro provides excellent coverage from a nearby station.