I enjoyed the Constantine pilot, though it's not the strongest. It's kind of a mix between the film, Supernatural, and the watered-down New 52 Constantine book. It does stay close to the comic book stories from the JC/Hellblazer days (though they still mispronounce the name) but in a less cynical-and-dark fashion.
I understand it is an NBC show, so smoking is out of the question and all, but I think it needs to embrace more grimness and Punk Rock attitude in order to stand out from the other genre shows (I think the archetypal character of comic book horror adventures deserves that little).
Anyway, solid start, way better that The Flash.
Also, Dr. Fate's helmet and Social D's version of Ring of Fire were nice to spot!