(Superhero ones, anyway)
I enjoy comics. At the same time, I fell a little bad about it. Not that I have issue with comics as a medium, but rather with the way their plots are handled.
It is very difficult in comics to have a central character who grows and changes. Any character development or major changes to tone, style, or canon will likely be lost when the next writer takes over. They definitely will be in the inevitable reboot. While some changes may be made to secondary of tertiary characters and actually stick, there is little hope for the primary character(s).
This is why limited series like Watchmen or Sandman succeed (though this is being screwed up) - they allow for one complete narrative with a definite resolution. However, this is by no means the norm. Instead, plots are drawn out indefinitely
If a series is not limited, the is little hope of success. Story arcs come to an end, but they rarely have any lasting impact. Thus Batman or Spiderman fights the same ten villains over and over, in about the same manner. They've been around for too long, and are no longer controlled by a permanent creative team. So while long-lasting and creator-owned comics like Hellboy or The Goon can still work, publisher owned creations have little chance to go a new direction, or even to bring back the energy and creativity they once had.
Admittedly, publishers have been trying to deal with this, with mixed results. DC killed off their three biggies (Batman, Wonder Woman, and Superman) but that hasn't really lasted, and they haven't introduced any new, interesting characters. Marvel has had a number of continuity wide events, but with few lasting changes.
How to solve this?
-End shared universes. If a storyline for a single title wants to expand beyond a certain point into events with permanent consequences, it can't under this setup. Nor do people stay dead. This should change.
-Limit series length. If someone wants to to a second series, like a television program, that's fine, but it should have to deal with permanent consequences from the first. This would allow creative teams to make permanent changes without them being undone by the writers that follow.
-Allow creative teams to start fresh series with fresh characters. Stop recycling material from the fifties.
That's about it.