I will say that the comics/graphic novels that have been released based on the books seem to be a more faithful adaptation to the source material, both in story and in artwork. They aren't limited by time or by budget, and can more effectively elaborate on back-stories that are either glossed over or completely ignored in the show. The characters and settings seem to be more accurately portrayed/drawn, more closely resembling descriptions in the book. For example, Tyrion looks a lot less attractive and charismatic than Peter Dinklage, Lysa Tully-Arryn isn't super-skinny like Kate Dickie, and all the characters seem to be drawn closer to their book age than most of the actors playing them (as in, all considerably younger), especially Daenerys.
I highly recommend it for people who want more info on the world of GRRM but don't have time to read the books. It's a great compromise between the screen and written word.