For anyone looking for a unique experience on a day when lots of restaurants will be closed, Nomiya is running an auction for places at its 12 person table for either lunch or dinner on Christmas eve, Christmas Day and New Years.
I've been for both lunch and dinner. While the food was interesting, it was good but not great. What was great was the view of the Eiffel Tower right outside the floor to ceiling windows and the mingling with guests, both local and visitors.
Here the link for the Christmas Day dinner:
Just look around the site to bid on any of the other meals.
And here's the link for our pictures on Facebook from our dinner in October. This was a very fun evening with memories and pictures to last a lifetime!
Just an alternative to some of the other Christmas/NYE suggestions in Paris.