Phil Phantom—known in the alleys as "The Whispering Wraith"—is not your average paranormal investigator. He is a conflicted medium, a cynical private eye who happens to be dead. Depending on the continuity, Phil is either a man cursed to walk between the veil of life and death, or a ghost using unfinished business to solve the crimes the living cannot. The "best" stories leverage this duality: they are equal parts hard-boiled detective fiction and existential horror.
Given the non-linear nature of the series, you do not need to read in chronological order. Based on fan polls and critical reception, here is the recommended reading path: phil phantom stories best
"Thank you, Phil," she whispered. Then she kissed him on the cheek—the first warm touch he'd felt from a client in years—and vanished, not into shadow, but into the morning light. Phil Phantom—known in the alleys as "The Whispering