Twisted City by Jason Starr
Hard Man by Allan Guthrie
American Skin by Ken Bruen
Pariah by Dave Zeltserman
Caught Stealing by Charlie Huston
All great, nasty, violent novels by authors with plenty of other great work. Worth looking into.
Modern Private Eye:
Saturday's Child by Ray Banks
The Guards by Ken Bruen
Darkness Take My Hand by Dennis Lehane
Right as Rain by George Pelecanos
Already Dead by Charlie Huston
Books that fuck with the private eye tradition or exemplify what can be done within the genre.
The Cleanup by Sean Doolittle
The Pistol Poets by Victor Gischler
The Wheelman by Duane Swierczynski
Yellow Medicine by Anthony Neil Smith
Deadfolk by Charlie Williams
Dark, criminal-centered novels but not "noir" dark. Some of them are pretty funny too.
The Wounded and the Slain by David Goodis
Friends of Eddie Coyle by George V. Higgins
Killer Inside Me by Jim Thompson
Last Good Kiss by James Crumley
The Switch by Elmore Leonard
All novels by crime legends that many modern authors will cite to you as major influences of theirs.