A Dirty Job — Christopher Moore

Charlie Asher is a pretty normal guy with a normal life, married to a bright and pretty woman who actually loves him for his normalcy. They're even about to have their first child. Yes, Charlie's doing okay--until people start dropping dead around him, and everywhere he goes a dark presence whispers to him from under the streets. Charlie Asher, it seems, has been recruited for a new position: as Death.

It's a dirty job. But, hey! Somebody's gotta do it.