Bon soir "Mademoiselle."

"Je suis Mademoiselle!"

A few provinces in France are retiring the term "Mademoiselle," and women there have conflicting feelings.  Some want to keep it in casual contexts; some like Catherine Deneuve are outright fans.  Apparently, calling an aging granny "Mademoiselle" will really put a lift in her step.
http://www.newyorker.com/online/blogs/lauren-collins/2012/02/adieu-to-mademoiselle.html

Mademoiselle does seem to have a little more je ne sais quoi than Ms.  But maybe we need to go back to our British roots for a form of address that will boost our spirits: Your Royal Hotness?