I don't pretend to be a terribly good analyst of these things, but I must say my over-riding reaction was a combination of three factors, two good, one less so: pleasure from seeing a decent adaptation of a book I greatly enjoyed, pleasure at seeing my native Ulster's landscapes transformed from sticky Irish mud to a landscape of fantasy and mystery, and deep puzzlement as to who the target audience for this show is meant to be.
The show seems at present to be very much the Sean Bean / Eddard Stark story, along with his two younger, brighter children (I mean Arya and Bran, very effectively portrayed by Maisie Williams and Isaac Hempstead-Wright; Rickon from the books is abolished), and then the parallel story of Emilia Clarke/Daenerys over the ocean. This obviously means downplaying some of the other viewpoint characters, but really these are the most interesting ones, apart from Tyrion who we don't see a lot of in Episode One (though Peter Dinklage shines in every scene). It is precisely the centrality of the kids that makes me wonder about the target audience; Martin's books are not children's books, and the TV version is definitely not a children's programme, so I wonder if adult viewers will really be able to identify with the smaller people.
As I said at the top, I liked most of the adaptation in terms of how it brought the book to life for me, but the Wall/Jon Snow/Catelyn subplot didn't quite seem to me to come off. Michelle Fairley's chemistry with Sean Bean is a bit variable (by contrast, she's much better with their supposed children, which is just as well, considering). Richard Madden is even more of a cipher as Robb Stark than the original character is in the books. And I know that the Northern Irish climate is to blame for this, but the Wall didn't quite seem cold enough to me (other than that, the show looks absolutely gorgeous).
On the plus side, the Daenerys/Viserys/Drogo realisation is fantastic. Again, I have the advantage of knowing what is to come, and that Daenerys' rise will be a contrast with the fall of all the Starks and Eddard in particular. If I didn't know that she has better times ahead, it would be quite hard to tolerate the way in which she is used as a piece of dynastic meat by her brother and the man she is forced to marry, even more viciously on the screen than in the books.. Emilia Clarke is effective and memorable as the sacrificed virgin; I hope she's able to keep it up when she becomes the warrior witch-queen.
I also liked the music, and the opening titles, showing the interlocking primitive politics of the kingdom as clockwork mechanisms, are at least memorable even if not quite technologically correct. And I'll watch the next episode, of course.