Just finished reading "In the shadow of No Towers" by Art Spiegelman. I've been a fan since Maus and if you find yourself stuck for some books you need to pick up Maus (and Watchmen, and Bone).
But if you don't manage to pick up a copy of No Towers, do yourself a favour and look up work by this guy:
>>>gustave verbeek<<<
He was one of the earliest innovators in comics whose short stories, "The upside-downs of Little Lady Lovekins and Old Man Muffaroo" were an ingenious experiment in compression in which the story would begin in the start of the strip and then halfway through the strip, the reader would turn it upside down and the strip would continue til the end. It was like Escher writing Snoopy. Amazing stuff.
Check this out: >>>The Thrilling Adventure of the Dragon<<<