I can recall reading only one of Robert Penn Warren’s books but that book by itself warrants inclusion on this list. All the King’s Men was a Pulitzer Prize winning book from 1947. Here’s the Goodreads.com synopsis:
all the king's men

More than just a classic political novel, Warren’s tale of power and corruption in the Depression-era South is a sustained meditation on the unforeseen consequences of every human act, the vexing connectedness of all people and the possibility—it’s not much of one—of goodness in a sinful world. Willie Stark, Warren’s lightly disguised version of Huey Long, the onetime Louisiana strongman/governor, begins as a genuine tribune of the people and ends as a murderous populist demagogue. Jack Burden is his press agent, who carries out the boss’s orders, first without objection, then in the face of his own increasingly troubled conscience. And the politics? For Warren, that’s simply the arena most likely to prove that man is a fallen creature. Which it does.

But while All the King’s Men was Warren’s best known work, it is far from being his only significant writing. Warren is the only person who has won a Pulitzer for both fiction and poetry. From his wiki:

Robert Penn Warren (April 24, 1905 – September 15, 1989) was an American poet, novelist, and literary critic and was one of the founders of New Criticism. He was also a charter member of the Fellowship of Southern Writers. He founded the influential literary journal The Southern Review with Cleanth Brooks in 1935. He received the 1947 Pulitzer Prize for the Novel for his novel All the King’s Men (1946) and the Pulitzer Prize for Poetry in 1958 and 1979. He is the only person to have won Pulitzer Prizes for both fiction and poetry.[1]

Looking through Goodread.com’s list of Warren’s books shows an interesting mix of fiction, poetry, children’s books, essays, and general non-fiction. A couple of his other novels that look as if they might be good reads are Band of Angels and The Cave.

Band of Angels is the story of a young woman in pre-Civil War Kentucky;

Amantha Starr, born and raised by a doting father on a Kentucky plantation in the years before the Civil War, is the heroine of this powerfully dramatic novel. At her father’s death Amantha learns that her mother was a slave and that she, too, is to be sold into servitude. What follows is a vast panorama of one of the most turbulent periods of American history as seen through the eyes of this star-crossed young woman.

The Cave is a story of a:

…young man trapped in a cave in fictional Johntown, Tennessee. His predicament becomes the center of national attention as television cameras, promoters, and newscasters converge on the small town to exploit the rescue attempts and the thousands of spectators gathered at the mouth of the cave.

If The Cave offers a familiar scenario, it should. While Warren’s book is set in 1959, Trapped! The Story of Floyd Collins was a real life media spectacle from 1925. The Collins story partially inspired a Kirk Douglas movie from 1951, Ace in the Hole.

A few of Warren’s books of essays also look to be interesting reads. Among these are The Legacy of the Civil War, Jefferson Davis Gets His Citizenship Back, and John Brown: The Making of a Martyr.

Warren’s Pulitzers for Poetry were for Promises: Poems, 1954-1956 and Now and Then: Poems, 1976-1978.

Most of Warren’s IMDB page covers various versions of All the King’s Men although there was a TV movie version of Band of Angels from 1957 or ’58 starring Clark Gable, Yvonne De Carlo, and Sidney Poitier.

The 1949 film version of All the King’s Men is the best known starring Broderick Crawford and winning the Academy Award for Best Picture, Crawford for Best Actor, and Mercedes McCambridge for Best Supporting Actress. It also had nominations for Best Director, Best Writing – Screenplay, Best Film Editing, and Best Supporting Actor.

Picture from Chris Drumm licensed under Creative Commons