There's great Terry Pratchett, and then there's, well, even greater Terry Pratchett. Reaper Man is in the latter pantheon.
While I have read all of Terry Pratchett's Discworld novels and enjoyed most, none are as moving and funny as Reaper Man. Pratchett succeeds here in doing what many authors attempt and at which few succeed--using parody and satire to convey a powerful emotional punch.
Pratchett's hilarious and poignant picture of the anthropomorphic characterization of Death entices the reader into a false sense of security and then, when you are least prepared, unleashes a devastatingly insightful and positive message about the human soul and condition.
While I suspect Reaper Man may be somewhat inaccessible to those unversed in the context and language of the Discworld, it remains one of my favorite works of any genre. It is worth reading the entire series for this one title alone.