Scott and I have visited France several times, but unfortunately never together (we'll have to do that in the future!). Paris is really a city that is full of romance and a unique vibe that is near to unmatched anywhere else.
I can't recall at the moment. The last time I visited I stayed with Steph and Jerry when they were there as expats.
Musee d'Orsay (full of impresionist paintings)
Notre Dame Cathedral
Versailles (a quick trip outside of Paris, but well worth it)