Benz stated that she had to get around twenty vaccinations before she could go to Southeast Asia to film Rambo and that it was a very sweltering and exhausting film experience, although she is grateful that she did it, and that she had fun with it. In fact, Sylvester Stallone cast her as Sarah because he is a huge fan of her show, Dexter.
She is best known for her roles as Darla on Buffy the Vampire Slayer and Rita Bennett on Dexter, for which she won the 2006 Satellite Award for Best Supporting Actress and the 2009 Saturn Award for Best Supporting Actress.
She has also starred on the series Roswell, Desperate Housewives, No Ordinary Family and A Gifted Man. Her film roles include Jawbreaker, The Brothers, Rambo, Saw V, Punisher: War Zone, The Boondock Saints: All Saints Day and Bedrooms.