Donald Westlake, writing as Richard Stark, put out 24 incredible Parker novels and 4 related Grofield novels. There is already a site with an enormous amount of information about the Parker franchise: Trent’s The Violent World of Parker. There’s also a great website, the official Westlake website, maintained by Westlake’s son, which has a ton of information about both the Parker series and Westlake’s other work: DonaldWestlake.com.
The Parker Novels
The Hunter, 1962
The Man with the Getaway Face, 1963
The Outfit, 1963
The Mourner, 1963
The Score, 1964
The Jugger, 1965
The Seventh, 1966
The Handle, 1966
The Rare Coin Score, 1967
The Green Eagle Score, 1967
The Black Ice Score, 1969
The Sour Lemon Score, 1969
Deadly Edge, 1969
Slayground, 1971
Plunder Squad, 1972
Butcher’s Moon, 1974
Comeback, 1997
Backflash, 1998
Flashfire, 2000
Firebreak, 2001
Breakout, 2001
Nobody Runs Forever, 2004
Ask the Parrot, 2006
Dirty Money, 2008
The Grofield Novels
The Damsel, 1967
The Dame, 1968
The Blackbird, 1971
Lemons Never Lie, 1971