I've read a few of his.
Mostly his Westerns, though.
"The Law of Randado", "Gunsights", "Hombre", "Valdez Is Coming" and "Forty Lashes Less One".
I've also read some of his contemporary novels,
"Out of Sight", "Get Shorty", and its sequel, "Be Cool".
Here's his booklist from his website:
The Bounty Hunters (1953)
The Law at Randado (1954)
Escape from Five Shadows (1956)
Last Stand at Saber River (1959)
Hombre (1961)
The Big Bounce (1969)
The Moonshine War (1969)
Valdez is Coming (1970)
Forty Lashes Less One (1972)
Mr. Majestyk (1974)
Fifty-Two Pickup (1974)
Swag (1976)
Unknown man No. 89 (1977)
The Hunted (1977)
The Switch (1978)
Gunsights (1979)
City Primeval (1980)
Gold Coast (1980)
Split Images (1981) Cat Chaser (1982)
Stick (1983)
LaBrava (1983)
Glitz (1985)
Bandits (1987)
Touch (1987)
Freaky Deaky (1988)
Killshot (1989)
Get Shorty (1990)
Maximum Bob (1991)
Rum Punch (1992)
Pronto (1993)
Riding the Rap (1995)
Out of Sight (1996)
Cuba Libre (1998)
Be Cool (1999)
Tonto Woman (1998)
Pagan Babies (2000)
Fire in the Hole (2001
Tishomingo Blues (2002)
http://www.elmoreleonard.com/opus/books.htm