The Solar Pons Series
by August Derleth

This bookshelf entry is in honor of the entire August Derleth-authored Solar Pons series (I’ve not read the Basil Copper-authored Pons stories). I think it’s the best Sherlock Holmes pastiche out there.
I also happen to own a copy of the Mycroft & Moran edition of The Chronicles of Solar Pons, which is why I chose its cover to represent the series.