I'm almost done with the 5th book in the Game of Thrones universe. I'm sad that I have to wait for the next installment. Overall I have been very impressed, I haven't been this emotionally attached to a fantasy series in many years. I listen to the audiobook in the car, then read the paper version at home just to get to the next chapter. There's slow spots, inevitable in a ~5,000 page book, but they are heavily outweighed by some seriously shocking, touching, or hilarious moments.
The HBO series is also excellent, but just a little different. I think it is made much better by knowing the books, there is a ton of excellent backstory and context that is necessarily left out in the shorter TV scripts (and some excellent shortcuts to show as much as possible in the visual medium). Like the LOTR movies, I think the TV series is the best that can be expected of converting one art to another. I hope they keep the quality high and I can't wait to see certain things put on the screen.