Mary

.
 * Mary Magdalene, who may have done sexy things with Jesus
 * Mary (Mother of Jesus), who somehow got pregnant.
 * Mary Baker Eddy, who, much like L. Ron Hubbard, started a religious cult.

Lesser known

 * Mary Lou Bruner — batshit crazy Texas politician
 * Mary Celeste — a merchant ship that showed up with its crew missing
 * Mary Landrieu — former Senator from Louisiana
 * Mary Marshall — Canadian medium with a bad sinus problem
 * Mary Stewart Relfe, who made a load of silly prophecies.
 * Mary Whitehouse — Christian pro-censorship campaigner