In honor of Hellblazer's 20th anniversary Vertigo will be releasing Hellblazer: Pandemonium, a new graphic novel written by original series writer Jamie Delano and illustrated by Jock. 

Delano wrote the first 40 issues, taking John Constantine from a secondary role in Alan Moore's Swamp Thing to a fully fleshed-out character.  Since Delano finished his run, Hellblazer has had a host of top writers including Neil Gaiman, Grant Morrison, Garth Ennis, Brian Azzarello, Warren Ellis and others.