Why is this so good? Probably for the simple reason that Jamie Delano, Garth Ennis & Alan Moore are on board. These 2 made the comic I loved soar when I subscribed to it all those years ago. That's right, this is no Keanu Reeves version of our favorite Hellblazer. This is the real deal. His compatriots are back. His story arc and background story intact. I just finished episode 1 and like Gothem having Frank Miller & Bob Kane (probably the best writers of Batman comics and going way back ) on the writing staff, this show Constantine will be appreciated by fans for what hopefully will be a sustained effort at excellence in writing and faithfulness to character. The Hellblazer of Alan Moore and Garth Ennis is a deeply flawed and nuanced John Constantine and with Chaz and Zed at his side this wrecking crew are sure to make a dent in hell's plots.
Other Comic luminaries that worked on the monumental character are Dave McKean, Grant Morrison, Neil Gaiman and Stephen Bissette. Let's hope this television series will do a fitting tribute to the excellence of writing and artistic talent due to its pedigree.