Well, that was an incredibly dramatic episode!
The killing of Varys seemed a waste - Dany announced herself as queen, while stood next to Jon who everyone present knew was the rightful heir.
The attack on the fleet - out of the sun - was daring, but the dragon bursting through the walls from behind and over the Golden Company was a great moment. The whole tension about ringing the bells was superbly done, and the expressions on the Lannister officer as you could see him deciding to surrender was great.
For a moment, we had the joy of victory - and then the horror of revenge by Dany's forces.
Her dragon attack on the city itself was horrifying and well done for it - we didn't even see Dany, but it's clear she's lost it. I've mentioned in the books how she never seemed to learn how to rule when overseas, and here it's clearly demonstrated that she is not fit to rule, and mustn't be allowed to rule.
The final duel between Gregor and Sandor was brilliant - such a dramatic backdrop, and totally deserving of the fight.
Cersei and Jaime was a little disappointing after all the prophecies of the Valonqar, but c'est la vie.
Thought Arya was a goner and Jon finding her body would make him personally see to the end of Dany's rule. Now Arya has escaped the city, it remains to be seen just how everyone is going to deal with Dany.
Btw, before I watched this I heard a lot of news reporting about people being unhappy with how Game of Thrones went this season, but so far I've thought it was really good - this episode was quite fantastic for its effect - so I'm not sure what the complaints about. Then again, I can start reading this thread now so perhaps I'll get to see.