If you like or don't mind the random nudity, sex(fairly non graphical), violence, blood and lite gore then the story is pretty decent, the characters are at least partially likeable and some of them well defined(at this point, this gets a little better in the books later on).

It is lightly based on fantasy. Just barely, the rest is somewhat medieval intrigue and with doses of historical epic, and a bunch of other stuff.

It's certainly decent, we have enjoyed watching it here.

As I have no clue where the show will go, from the book perspective, if you don't think you will like a show with power struggles, backstabbing, and spying then this isn't for you probably.