I've read somewhere that the title will be "The final War", but not sure about how reliable that is.
The episode title was "The Bells." But it could have had as a subtitle "burn them all to hell."
The episode itself was quite epic--it starts with Varys being sentenced to death and Tyrion both betraying him (to save his ass) and offering him a last minute kind gesture. But as Varys is torched by Drogon, his warning sounds as prophetic as Melisandre's. Tyrion makes a last minute arrangement to save the population: if Circei rings the bells and surrenders, Daenerys won't set them all aflame. After Drogon avoids all the successful marksmanship of the iron fleet in episode 4 and blows all scorpions to nothing then brings down the gate, Cercei's army actually lays down their weapons.
And at that moment, the show decides to fulfill one of the worst fan theories, that of the mad queen. Daenerys decides to blow up civilians and surrendered soldiers, and the Unsullied and Dothraki are only too happy to follow in their slaughter. In the mayhem Arya and the Hound have a touching scene, where he tells her she doesn't want to end up like him, fueled only by revenge. She leaves Cercei alone and tries to escape the falling city first, then helps civilians as much as she can. And in another moment of fan expectations fulfilled, the Cleganes fight and both fall to their death. And the Lannister twins die together, as they came to the world.
Through all this, it becomes obvious to Davos, Arya, and clueless Jon Snow that Daenerys has lost it. I guess the show needed her to do something so horrific to have them turn against her. Daenerys early in the episode did tell Tyrion (who continues his stupid moves and miscalculations) that he never even considered why Sansa told him the secret, and he in turn told the master of whispers. Sansa pulled a classical Littlefinger move, which shows she has learned from all the villains she has been around.
Overall it is obvious what kind of a fight we still have ahead, although frankly nobody else has much of an army now, so to off Daenerys it has to be done in Arya style. But who will sit on the iron throne? At this point, I think Sansa would be the most suitable.