The film versions of those two were released the same year and the wrong one became famous. After Dark is still unknown and so good.
Was in a different spot in my life when I read Thompson, but maaan did it resonate then. Like Bukowski/Fante-levels at the same time, but again I was in a different space (semi-emotionally trapped on a Great Lakes 1x1.5 mile island for several months). Just look at your image.
The Killer Inside Me was probably his first great... and a pretty bad movie.
From Wikipedia: The writer R.V. Cassill has suggested that of all crime fiction, Thompson's was the rawest and most harrowing; that neither Dashiell Hammett nor Raymond Chandler nor Horace McCoy ever "wrote a book within miles of Thompson". Similarly, in the introduction to Now and on Earth, Stephen King says he most admires Thompson's work because "The guy was over the top. The guy was absolutely over the top. Big Jim didn't know the meaning of the word stop. There are three brave lets inherent in the foregoing: He let himself see everything, he let himself write it down, then he let himself publish it."