Just from a list of names that have crossed my mind lately... Eliminate your favorite, the last one remaining will be the least popular.
Anatole, Cato, Cyril, Léonard, Léopold, Maddock, Ozias, Rupert, Ugo
Catherine, Cristina, Isabel, Luciana, May, Roselaure, Tirzah, Una, Vashti