3. Carol
Similar to Beth, Carol just hasn't been given much to do. She is constantly distraught and on the verge of tears in the aftermath of losing her daughter Sophia (one of the very first shocking character death reveals in season 2). Unless she was getting really deep with Daryl, consoling a dying T-Dog, or giving Andrea advice about The Governor, she's been more of a liability to Rick than anything else. She has toughened up a lot over the course of the show, but she's no Michonne or Andrea when it comes to taking out walkers. In the comic book she eventually commits suicide in the prison, which may be a little too dark a direction for the TV show to take. But one way or another, Carol could die with little consequence.