Rewatching it too, halfway through season 6.
I think my ranking would be: 3, 6, 1, 4, 2, 7, 5
3. The Red Wedding, Dany torching Astapore, Jaime and Brienne, every scene involving two or more Lanisters, Jon and Ygrite. Even the little moments like Sharine and Davos are great. I guess the Ramsy/Theon arc is the weakest, but even that one I find interesting.
6. Still rewatching this season, so it may move up or down, but episodes 9 and 10 are possibly the best two episodes of this show period. There's also Dany buring the Khals, Hodor's unbelievable send-off, the Tower of Joy, Jon and Arya reuniting, Jon's resurrection, and Jon killing the traitors. On the downside, Arya's plot at the House of Black and White ends absurdly with her surviving multiple stab wounds to the gut. There's still some Dorne crap, and while I don't hate the High Sparrow arc, I'm also not in love with it.
1. Dany's season 1 arc might be the best single arc of the entire saga. Ned's arc is compelling as is Arya's, and everything with Tyrion is awesome. The drama, manipulation, and back stabbing in King's Landing is interesting, especially Varys and Little Finger. The stuff with Robb in the last few episodes are my favorite Robb moments. On the downside, there's a shit-ton of exposition and some of the actor's are still settling into their roles. It's not Jon's most interesting season either.
4. Everything in King's Landing is off the hook. The Purple Wedding, Tyrion's trial, everything involving Oberyn, the Mountian vs. the Viper, etc. Arya and the Hound is another great arc. However, there's not much else that captures me this season. Dany's arc is solid but unspectacular and the same can be said for Jon's. The Watchers on the Wall is by far the weakest GOT setpiece battle. Stannis doesn't do shit until the final episode.
2. Again, everything in King's Landing is great. Again, anything involving two or more Lanisters is great. Tyrion is just awesome this season. The stuff at Harrenhall is also phenomenal. Ayra and Tywin especially. This is Stannis's best season, and the stuff with Renly is engaging as well, prior to his death. Jon's arc is more interesting than season 1, but still not engrossing. Not a memorable Robb arc. By far Dany's worst arc in Qath.
7. Obviously, it's ranking could move up or down based on the finale. Lots of amazing set pieces, but less attention to detail. It's clear that the show-runners are writing off of bullet points, filling in the blanks, and feeling the pressure of time. Too many key moments are rushed and too many details are being overlooked (i.e. Tyrion and Jaime reuniting), which I think could have been avoided by flushing this out into 10 episodes. Still, there have been a ton of unforgettable moments: the slaughter of the Freys, Jon and Dany meeting, everything with Euron, Cersi mentally torturing Elaria, Lady Olena's farewell, Dany vs. the Lanisters (best battle scene of the saga thus far), Viscryion dying and turning into a whyte, all the Arya/Sansa/Little Finger machinations. On the other hand, the central plot of this season is going beyond the wall to steal a white walker in order to convince the ruler with the smallest and weakest army into a truce.
5. Too many dull arcs. Dorne sucks, Mareen stalls, we get the weakest Kings Landing arc, and the weakest Tyrion arc (although I still mostly like it). On the other hand, I really enjoy Arya's first season in Bravos. Jon's arc is pretty solid and finishss strong. The setpiece at Hardhome is pretty awesome, albeit overrated (not even close to the best episode or setpiece). The final stretch of Stannis is absolutely excellent. Shareen's death was the most disturbing and devastating moment in the entire saga, and seeing Stannis face his fate the next episode was beuatifully redeeming. Jon's assassination was similarly unsettling.