Eh, the books had just as much sex in them as the show does, from what I hear. I find it mildly annoying that people are more shocked at sex on the screen then sex in books.
Game of Thrones is the best television show currently running, in my opinion. I didn't watch much of the first season, but I watched the second and am watching the third. There is a certain amount of nudity (and violence, don't forget violence) so that probably renders it unwatchable for many of you. It's a shame, because the acting, production, and plot are the best I've ever seen on any TV show, ever. ( The second season was a bit meh at points but the third has been absolutely fantastic ) The real highlights for me are the performances. The show has to feature a gigantic ensemble cast, and they are all incredible, especially Peter Dinklage ( of Prince Caspian fame

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I dislike much of the nudity, because it often seems gratuitous and offensive. The violence is extreme, but it's usually plot-driven, and the show is great at showing the consequences of violence and other wicked behavior; the anguish of mothers, the rebellion of children, and the finality of death.
Overall, I wish I could recommend it, but if you know that certain elements would cause you to stumble, then please steer clear. Even the best TV show that has ever been isn't worth the cost of a hardened conscience or a shaken moral standard.