This almost goes without saying at this point in the run, but this is the best book DC is putting out right now. And it may be better than any book Marvel is putting out. Simply put, Grant Morrison is a mad, evil, dastardly kind of genius and Quitely has proven every bit his Mutley for what is shaping up to be one of the all-time great Superman stories. As blasphemous as it may sound, this may top Alan Moore's “Whatever Happened to the Man of Tomorrow?”.
For proof, look no further than Morrison and Quitely's brilliantly imagined Bizarro World and the Bizarro rendition of the Star Spangled Banner. With Morrison and Quitely's Bizarro World, they have created something that is at once viciously satirical, wildly absurd, and at the same time completely fleshed out and realized. If you aren't staggered by the comedic genius of their Bizarro-version of the Justice League then you may want to check into your local mortuary, because you may already be dead.
But what takes this book to that next special level is that behind the whimsy lies an extremely wistful story that puts more soul back into Superman than I remember in my lifetime. Through Zibarro, Morrison articulates beautifully and brilliantly Superman's outsider status in a way that so many better writers have failed. This series is full of gut punching moments like that, tackling almost every element of what makes Superman so super. If Frank Miller stripped Superman down to the status of a tool, then Morrison and Quitely's All-Star Superman can be considered a staggeringly significant re-animation.