My problem with A Game of Thrones was that everybody in the A plot was a self-destructive idiot, while the B plot -- the Conan and the Horse Lords stuff -- was dull, which is quite the achievement when one's dealing with rampaging barbarian tribes, mysterious witches and legendary dragons.
The good news about the TV adaptation is that it's very faithful to the book. The bad news about the TV adaptation is that it's very faithful to the book.
Of course, everyone loves it, and a friend of mine posits the cretinous ramblings of the cast as a plus point, saying it's more realistic somehow. No. It's not realistic, rather it's the equivalent of those rubbish slasher movies where teenagers wander off alone to investigate that noise in the cellar. Now I'm quite a fan of the rubbish slasher movie, but this one is running to five hours and counting, and that's pushing it.
In fairness, the TV show does improve on the book in some places. The cast is excellent -- aside from Lena Headey, who does her usual squinty, frowny "I'm trying to remember something really obscure" acting -- and the writers have the benefit of knowing what's coming up in the next few books, so they've gone back and fleshed out some of the characters with that in mind.
They're all still idiots though, and I can't watch any more of them doing incredibly stupid things just so the plot can progress.