If there is an Iron Throne at the end the best candidate would be Stannis. I really warmed up to him in ADWD.
But the shows portrayal of HotU has me thinking that Danny and her Dragons is going to destroy KL. Looked like she gave it the Harrenhal treatment..but it was interesting that it was snowing inside...maybe a reference to Jon or the Others potentially making it to KL which is why Danny burns it down?
In a perfect world...Sansa rebuilds Winterfell, Stannis rules Storms End, Jon stays LC, Jorah returns to Bear Island and Danny goes to Dragonstone
Robb should've never went w/ the whole King of the North thing...just teamed up w/ Stannis and went down to KL and killed everyone and went back to Winterfell