2. Jesse
The amount of suffering inflicted upon Jesse Pinkman across the course of the series is truly mind-boggling. Firstly, his girlfriend was allowed to die from his business partner's lack of concern, and that same partner forced him to murder Gale Boettecher in cold blood. He then spiraled into a frenzy of drug abuse and crippling depression which culminated in his cash-throwing epic breakdown before being used as a pawn by the Feds, kidnapped and tortured by Nazis and most recently forced to watch the murder of his girlfriend. Amazingly epic for a character that was originally intended to die early in the series. After enduring all of that, Jesse deserves to escape his horrible circumstances for a happy life with Brock, and it would be enormously satisfying to see him rid himself of his drug issues once and for all. Also, it would be great to see him reconcile with the family that previously rejected him and have them accept Brock as their new grandson, whom they promptly set about spoiling with enormous piles of toys and video games. It'd also be a nice touch for the final shot of Jesse in the series to be him playing MarioKart with Brock, which is probably as happy as Jesse has ever been.