I voted Naruto because it is a valid possibility and what I would be happy with seeing as an ending, I know it's selfish. I truly believe that despite Sasuke's revelation of Madara being the real bad guy, he has done far too much to gain redemption or even pity from anyone in Konoha. I hope Naruto kills Sasuke in defence of the city and the lives of his allies and real friends. He lost the last fight against him and I don't want the series to end with Naruto being owned like that and left to live at Sasukes whim.
However, Naruto does not believe in unjustly taking lives and if Sasuke repents I could definitely see Madara as the one to kill Sasuke instead of Naruto. Then Naruto would have a final epic 1v1 with Madara. This ending would make more sense and allow Kishi to resolve everything to the satisfaction of many.
Something just doesn't sit right with me in allowing Sasuke to go from a dumb used emo traitor to a martyr and redeemed ninja. Though used, he enjoyed and did many of the evil things of his own free will. Sasuke is far too easily swayed and has been touched by evil, he needs to be put down in either case, I'd just be happier with it being at Naruto's hands, then the pain of having to kill his friend would lead him to an epic fight with the man pulling all the strings and manipulating everyone, Madara.