Bell garnered critical acclaim for her first major role as the title character in the teen noir drama television series "Veronica Mars" (2004–2007). For her performance, she was awarded a Saturn Award for Best Actress on Television. She reprised the eponymous role in the 2014 film continuation and the 2019 revival series. During her time on "Veronica Mars", Bell starred as Mary Lane in the musical film "" (2005), a reprise of the role she had played in the New York musical upon which the film was based. From 2007 to 2008, Bell starred as Elle Bishop in the science fiction drama series "Heroes". From 2007 to 2012, she voiced the titular narrator in the teen drama series "Gossip Girl".