I just started watching it, and researching it. George R.R. Martin apparently wanted to do an American version of Lord of the Rings. Why? Who knows? I've never been a LOTR fan. I've tried to read the series at least a dozen times and never gotten beyond pg 78 when I fell asleep from sheer boredom. The movies did the same thing.
So I was expecting the same from GOT. Wow, what a difference. The sadistic Joffrey (I think he was modeled after Caligula.). The incredibly Machiavellian dwarf Tyrion Lannister and his sometimes nemesis, sometimes partner the unctuous and condescending eunuch Varys are outstanding actors. Even the utterly disposable characters such as the wandering minstrel Marillon who sings to Joffrey and pays hideous price for it are unbelievable.
If you do watch it, watch at least 3 to 5 episodes so that you can begin to get the general drift and theme of the series.