I've always been on Team Daenerys but I think the odds of someone other than her sitting on the Iron Throne at the end of the show are increasing.

Some sort of twist ending with Sansa or Jon or Tyrion or Arya sitting on the Throne, or the NK killing all of humanity, might be pretty good/satisfying.

There was obviously a lot of talk about her line of succession and the fact that Dany can't (won't?) have children, and there are suddenly a lot of people in the picture with some sort of reasonable claim to the throne.

I'm not going to pretend to be an expert in Westerosi law and I'm skeptical of anyone else who claims to be, but I guess that the claimant with the strongest army wins out, generally. For instance, it is well known (I think) that Robert had many illegitimate children; it's not really a secret that Joffrey/Tommen weren't his children. House Baratheon has to have some survivors, I'm not sure how Cersei can legally lay a claim to being the ruler of Westeros, other than the fact that she was the de factor ruler under Tommen and the Lannister army follows her orders.