Here are more suggestions that your post reminded me of, although not available as Audiobooks yet.
Susan R. Matthews, An Exchange of Hostages, et al. Warning, extremely uncomfortable subject matter; approach with care but amazing.
Christopher Golden, the Peter Octavian series. First book is Of Saints and Shadows.
What can be said about the series that is not contained in the following sentence: Jesus Christ was the first vampire.
Nancy Collins, any of the Pretender books, especially Sunglasses After Dark, except A Dozen Black Roses.
Ian Douglas (aka William Keith), the trilogy of trilogies starting with Semper Mars.
Any book by Michelle Sagara/West.
Seanan McGuire, Incryptid series. If you are into filk, check out her CD Red Roses and Dead Things.
The wife recommends Barbara Hambly's series beginning with A Freeman of Colour. The Vogon prefers the Darwath series.