The comic book Hellblazer (Vertigo).
The artwork is usually adequate for this long-running series, and the stories are quite well written. In fact, it's hard to believe how certain comic books have plots, characterizations, and dialog more deftly executed than even good TV shows.
Forget the movie version of John Constantine. The actual chain-smoking, dead-mystical, comic-book guy will mess with your mind.
This four-issue arc -- "Freezes Over" -- is creepy, dark, readable.