system
Given the following post, respond as if you're commenting on Reddit:
human
[Game of Thrones] How desireable a wife was Sansa?

If Ned and Robert were not close friends would Sansa still have been considered a good match for Joffrey?  To me it doesn't seem like Winterfell wasn't that important or rich a region nor would they needed to marry to cement a political alliance.  Would Margaery Tyrell have been the first choice to cement a tie between the Tyrells and the Crown since they fought for the Targaryens?  If Sansa was not to be wed to Joffrey would she be acceptable to marry the heir to any of the other major houses?
gpt
First, the north is the largest geographic kingdom in Westeros.  That's pretty significant by itself.  

Second, think about Sansa and Jeoff's combined lineage, their child would be 1/4 Stark, Lannister, Baratheon, and Tully.  As well as grand niece/ nephew to the Arryn's. By heritage alone their child would be connected to five of the great houses and would be as connected a king/queen as is basically possible.  It would unify the kingdoms that have mostly acted separately since the Greyjoy rebellion.  

Oh also, she grew up with the Greyjoy heir, giving her a connection to that house too.