I loved Lee and Clem, but since everyone loves them (seriously, who doesn't? Why would you even play if you didn't love the crap out of that awesome little girl and that wonderful tortured man?) I picked the much-maligned Ben.
People forget how much it sucks to be a teenager. Your emotions are all over the place, your hormones are going crazy... he's old enough to not have any childlike resilience/adaptability to cushion him nor parents or guardians like Clem and Duck have, and old enough to comprehend the horror of the world he's living in, but not old enough to have years of life experience to strengthen his resolve. Lee and Mark and Lilly and every one of them have a mature perspective... Ben has nothing and no one during the entire story; he's alone. It's why I had Lee try to mentor him, not that anything ever takes before he dies.
He gets so much hatred, but really, he had it the worst out of anyone in the entire game.