I'll second the L. Sprague DeCamp suggestion and add The Goblin Tower
and The Fallible Fiend
to the list of his stuff.
Ditto on the Glen Cook 'Garrett, P.I' series with Sweet Silver Blues
, Bitter Gold Hearts
, etc. Think Travis McGee in a seedy Middle Earth, with all the books having metals in their title instead of colors. Very tongue-in-cheek riff on the crime-noir genre.