Alice! Because Alice is nice to Bella and actually tries to help and understand why Edward likes her. But Rose helps at the end, but then she only cares about the kid not Bells.
Alice! :D I would die to have her be my sister. (And I'm not pro-vamps, so anda know that means I would not give my ENTIRE life to be dead and always crave my family's anf friend's and ppl I don't know's blood.)