The Funny Books
Bookslut reports that Vertigo Comics has started to employ the graphic novel stand-alone book as a greater part of their repetoire. And thank God for that.
The one big step that comics could make towards being taken seriously as an art form is precisely this. While the serially issued comic has greater opportunity for character development, etc., it also means that the main characters need to be extraordinary people to whom extraordinary things happen constantly. That makes it easier to fall back on the superheroish format.
I've had some amazing reading experiences with standalone graphic novels, and I think good examples here are two of the ones I liked most, both by Neil Gaiman: Signal to Noise and Violent Cases. These were both serially published in their original form, but were really better suited for standalone volumes. Reading them all at once created an incredible reading experience. They're stories about more-or-less ordinary people involved in an ordinary event, one battling cancer while writing his last movie script, the other trying to make sense of his childhood memories. They both create literary events, and use the unique capabilities of the graphic novel format to create something unique. They would not be possible in open-ended serial formats.