Book Challenge-Day 7- Most underrated book

I feel like there are so many of these books out there.  BUT, I am going to just have to narrow it down to one, I know.  There is a series of books that I enjoy a lot, but very few people (at least that I know) have heard of it.

This book holds the story of a police detective named William Monk who wakes up in a room in a panic, not knowing whether he's in a workhouse or a hospital, not even knowing his own name.  They tell him that he was in a carriage accident, and that he used to be the best detective in London.   Throughout this series of books, he solves high profile murder cases, while learning how to be a detective again and learning more about the person that he was before his accident.  He is helped by several characters that come in and out of the series, but overall, I really enjoy these books.  I say these books are "underrated" because hardly anyone has heard of them, although most people have heard of Anne Perry AND they're overshadowed by the Thomas and Charlotte Pitt series that Perry also writes.  I enjoy these books, and the mysteries in them.  Most of the books in the series are excellent, but there are a few that aren't as good as the others.  This is an entertaining set of detective and mystery novels.