The wonderful Paris
Make sure you stay in a nice boutique hotel in a popular neighborhood like Latin Quarter or Le Marais.
They will be within walking distance of the Seine River, museums and Notre Dame. As far as museums go, don't miss Musee' d Orsay. The famous paintings by Renoir, Degas, Monet, Mother Whistler, etc. are all on the 5th floor of this museum. The cafes in this building also serve very good food at a faster pace than restaurants nearby. The Louvre is far too big and would take a couple of days to do justice.