The Dark Tower: the Gunslinger - The Man In Black was everything I've come to expect from the Dark Tower graphic novel series. The Man In Black is the "end of the beginning". It deals with Roland's relationship with Jake (just like in the novel), and Walter sends him on the path to the Dark Tower. I loved that it stayed true to the original story, but with the added bits you can only include in a graphic novel. The art very much suited the mood of the story, and Roland's appearance in The Man In Black was pretty much how I imagined it for the entire series.
I know there's another Dark Tower graphic novel. Last Shots I believe tells the story of Sheemie, so it's sort of a prequel/parallel story instead of a continuation. I wondered as I drew closer to the end of The Man In Black if there would be more graphic novels. The second novel, The Drawing Of The Three is one of my favourite Stephen King books and I'd love to see it in graphic novel form. However, there are eight novels. They can't all be adapted, right? I'm slightly obsessed with this series though, so if they write them, I will read them.