Why Sansa Stark should sit on the Iron Throne.
When the snows fall and the white winds blow, the lone wolf dies, but the pack survives.
While arguably all the characters of 'Game of Thrones' have developed in leaps and bounds, and several have good reason to hold a claim to the Iron Throne, it's Sansa Stark who is truly worthy.
Sansa is an intellectual pillar of strength but she didn't start out that way. At the beginning of the series, Sansa was a naive, idealistic, spoilt teenage girl. We were introduced to the character when she was 13-years-old, the eldest daughter and second child of Lady Catelyn and Lord Eddard 'Ned' Stark. Sansa proves her knack for poetry, embroidery and music among other lady-like pursuits and is excited to be married to Joffrey Baratheon. That is until he executed her father.
Sansa Stark was once a naive, idealistic girl with princess-like notions
Ned's death is a major turning point for Sansa. From there, she becomes a pawn trapped in the Cersei Lannister's game of thrones and play for power. She has no choice but to remain in King's Landing and is humiliated by Joffrey, but swears her love for him so that she can survive. Sansa is eventually married to Tyrion Lannister but escapes the family's custody when Joffrey is murdered by poison which, unbeknownst to her, she carried in a necklace gifted to her. From there, she stays hidden in the care of Petyr "Littlefinger" Baelish, who is obsessed with her. Sansa is nearly killed by Littlefinger's wife, Sansa's aunt Lysa, but Littlefinger kills her to protect Sansa (and himself).
Sansa is very much a passive character in her own story at first. And things go from bad to worse when Baelish arranges for her to be married to Ramsay Bolton. On her wedding night, she is raped by Ramsay and afterwards she is continually raped, beaten and psychologically tormented by him. It is the lowest point of all that has happened to her. From there, things can only go up.
When Sansa marries Lord Bolton, she suffers greatly but it also turns her into the pillar of strength she is today
From season six, when Sansa Stark makes the decision to retake her family home and exact revenge on those who abused her, there's no stopping her. Over the last number of years, she has learned a great deal from her enemies, as well as her friends. After escaping the Boltons, she reunites with Jon Snow, who totally underestimates just how much she's grown and how valuable her experience and knowledge is (because, obviously, he knows nothing). At the Battle of the Bastards, he is nearly defeated until his army is saved because Sansa called on the Knights of the Vale, thus proving that she's more warrior-like than we expected her to be. (In fact, for all the talk that Jon Snow should sit on the throne, he has to be bailed out a lot.)
Sansa learns the most from her relationship with Littlefinger
Ramsay's death marks another turning point for Sansa as he is the first person she has ever killed. She has the guy devoured by his dogs, an appropriate punishment given how torturous he has been to others. As her father did before her, she executes when it is right to do so. The same goes for Littlefinger, who has proven to have a tricky relationship with Sansa. He has saved her on multiple occasions but was also being responsible for her marriage to Bolton. However, his attempts to turn her against her sister Arya prove to be the final straw. Sansa realises that Baelish is only using her for his own game and advantage. Now she is a player in the game, no longer a pawn.
It has been teased that season 8 will see 'Game of Thrones' come full circle. With Ned having been portrayed as the idyllic king at the start of the show, it would make sense that his eldest (which Sansa is, now that his other descendants have died) becomes queen. Her, Arya and Bran make for a balanced, powerful and just ruling family. Their lone wolf father may have died, as has their brother Robb, but they're still here.
As for comparing Sansa to the likes of Cersei Lannister, Daenerys Targaryen, Brienne of Tarth and even Arya, who are typically considered the 'strongest' women on the show, Crystal Bell summarised it well:
"Sansa's greatest strength as a character has been her unwavering resilience. She was tortured and humiliated for seasons by the unhinged man-boys around her. She's been the subject of everyday sexism and misogyny since day one. And yet, she survives, even as armor-clad heroes fall before her. She is the show's survivor."
As we all known, to win the game of thrones, survival is the only way to stay in play. At the end of the day, the Iron Throne could simply go to the last one standing.