it would be exceptionally poor writing for Jon to die, be brought back, and die again. characters written like this usually end up to be invulnerable, this is why you get the frenzied charge in the Battle of the Bastards where he should have died twenty times over and have him find his way out of the bottom of a lake in the frigid cold, so my pick is Jon. Dany has seemed like the pick for so long that swerving it seems only logical and her learning that there is more in life than sitting on a throne would be good. Jon has the most legitimate claim to the throne in the entire series as well and "sullied orphan turns out to be royalty" is an oft-used trope. sleeper pick is Tyrion just because he'd probably be the best at it. I don't think Tyrion dies or even should die. really, I don't see Dany and Jon both dying so it's just likely to be one of them. you get any further down the line than those three and you're headed straight into "holy shit bad writing" territory. the people who made those odds are retarded anyway, in what world is Arya ever sitting on a throne to rule? other thing I could see is there not being a throne at the end. King's Landing will clearly be a battle point, what if the dragon rips a hole open in the throne room and burns the throne down. a dragon melted it to make it, it would be fitting for another dragon to destroy it. if that happens you might just see them go back to being independent kingdoms entirely and then I guess technically nobody sits on the throne.