A alternative, and better, ending for Game of Thrones:
Cersei still captures Missandei but kept her as a captive instead of behead her in front of Daenerys as a stupid and suicidal provocation. Meanwhile Daenerys and Tyrion argues how to gain her freedom, Cersei gives birth to her daughter and is happy for a few until Euron shows finally his true colors - his true plan was always join himself at the "Dragon Queen" - and kills her, and almost does the same with the baby when Jaime appears (thanks to the hidden tunnels of the Red Keep) and realizing what happened, slays him, saves little Joanna and freeds Missandei before depart towards Brienne who waits him outside the city.
But when Tyrion heards that his sister is dead, he coerces Daenerys to fly with Drogon above the Red Keep and intimidate the last remainings of Lannister armies, without knowing about the release of Missandei. Daenerys finally agrees and did it but then she commits her worst mistake: Blow dragonfire to a targeted objective, just to show her strength like her advisor said. Wildfire under the city unleashes and King's Landing disappears into the green flames.
Full of remorse for had killed accidentally thousands of innocent people (most of them smallfok, who D&D forgot she considers her CHILDREN too), Daenerys flies to the ruins of the Red Keep crying, only to infuriate at the discover that the Iron Throne stills. It's then when she orders Drogon melt it. After it, both leave the place and soon Westeros too.
Sansa wakes up and founds a note written by Jon, we don't see what it saids but she smiles. Meeting between Jon and Dany in the ship towards Naath, she cries at seeing him but he hugs her and whispers: "I was never made to be King of Westeros anyways"
A council reunites in The Trident and agree at the dissolution of the Seven Kingdoms along with a sealing of peace and borderlines statements to avoid fall in the same blood civil wars before the Targaryen Conquest (It will works? Who knows)
Sansa returns to Winterfell where she accepts being crowned as the Queen in the North but we can't see she is not happy, like she miss something. Then a voice from behind makes her jump and when she turns around we see Sandor in the doorframe and she runs to hug him.
Tyrion searchs for Jaime but when he finds him, he seems Brienne and his brother walking together in the beach of Tarth with Joanna. Tyrion watches the scene for a little bit before turn around and leave in silence.
Arya agrees to marry with Gendry but with the condition of do it in Winterfell. "Great, we would then wed the same day that your sister and her dog" Arya growls in disgust.
