I only got watching this last night, due to being away for Easter. I voted Above Average, as it was a solid, rather than spectacular return. And, having read the book, I know that there will be plenty of opportunities for an Excellent rating during this run.
Still lots of great stuff here all the same. The giant and the rest of Jon's arrival at the Wildling camp. Tywin and Tyrion. Bronn squaring up to the Kingsguard, not to mention his reaction to Pod's coitus interruptus (while Bronn is a great supporting character in the books, I think Jerome Flynn has actually made him even better onscreen). Maergary and Cersei's little jabs at each other.
And of course, the dragons, the Unsullied and Ser Barristan. I'm in agreement with those who say that the whole Whitebeard storyline wouldn't have worked onscreen as it did on the page, though it was interesting that some of the slave trader's lines, which were aimed at Whitebeard on the page ('tell the old man he smells of piss') were simply redirected at Ser Jorah instead.
I must say, it was great to see Ciaran Hinds, Liam Cunningham, Aiden Gillen and Ian McElhenney onscreen (and there are still the likes of Conleth Hill to be seen). A whos-who of Irish talent - even if Aiden Gillen's portrayal of Littlefinger doesn't quite hit the mark for me (much as I've liked him in other roles).