A Dirty Job is the book that made me fall in love with Christopher Moore. I have read/listened to other books of his, but this one got me hooked.
I recommend the Audio Book Version, specifically, because they worked in funky music that adds a ton to the experience.
The basic plot is: A second hand store owner loses his wife in childbirth, raises his new daughter, and unexpectedly becomes Death.
Definitely on my recommended list.