In addition to some of the classic venues, the Eiffel Tower, the Louvre, Notre Dame, Luxembourg Gardens, etc., we did a couple things I have not experienced in Paris before.
One evening we went to an organ recital at Notre Dame. While I enjoyed some of the older pieces, including Bach, most of the program was modern which was not to my taste. What was to my taste was this seemingly impromptu community art work of locks (each with two names written, presumably representing committed relationships) along the bank of the Seine.
And in an effort to keep the kids happy, I researched playgrounds in Paris which led us to La Villette, a huge cultural venue built some years ago on the site of an old industrial area. It featured a huge science museum, music hall, and lots of playgrounds with cool features. We spent the whole day there – much fun.