From his Slashdot interview (via jwz):
When you talk about movies, there's always that which bookstores live by; the book is almost always better than the movie. You could have no better case in point than FROM HELL, Alan Moore's best graphic novel to date, brilliantly illustrated by Eddie Campbell. It's hard to describe just how much better the book is. It's like, "If the movie was an episode of 'Battlestar Galactica' with a guest appearance by the Smurfs and everyone spoke Dutch, the graphic novel is 'Citizen Kane' with added sex scenes and music by your favourite ten bands and everyone in the world you ever hated dies at the end." That's how much better it is.