I recently finished the novel. Before that, I'd seen the movie and then read the manga. I liked all three forms of it. Personally, I'm glad I saw the movie first. I think I would've been disappointed in the movie if I had either read the manga or the book first, because of the stuff that was changed, or left out. Out of the three, I did like the manga the best (I was able to share the cost with some friends, so it didn't cost me a fortune). All three together do a decent job of telling the story. They all have their strengths and weaknesses, but I heartily reccomend them to everyone (who isn't afraid of a little gore)