O'Hara wrote mostly of the daily peccadillos and scandals that transpired in the early 20th century small town of fictional Gibbsville, Pennsylvania, located in the anthracite region of the Keystone State. Gibbsville rarely escapes mention in any of his works.
His best novel of all (my opinion) is 'Appointment in Sammarra' where we are treated, right off, to a young mover and shaker who spontaneously decides to chuck his iced cocktail into his old mossbacked boss's face, giving the old man a black eye. That's the sort of story that it is and I loved every word.
In 'Butterfield 8', an adventurous young and beautiful gal has an affair with an unrepentent executive. He unwisely ticks her off by leaving her some cash to get home on after one particular night of wild carousing and, as the guy's wife is away from the apartment, she lifts his wife's mink coat from the closet, just to cause this scoundrel a panic. It goes downhill from there. The 'Butterfield 8' thing is a reference to a phone number, (for those of us who are aged enough to remember that phone numbers used to begin with 'names' so that we could remember them better).
'Hope of Heaven' is a tale of Hollywood (and obliquely of Gibbsville) and a playwright is the protagonist. And since it's Hollywood, of course there follows plenty of underhandedness, scandal and O'Hara's semi-graphic trademark conveyance.
O'Hara loves to kill off his characters, and not necessarily the ones that you expect to die. Every time he abruptly pulls it off, I find myself rolling in the floor, howling with laughter, mostly at myself for not seeing it coming.
This triad of novelettes is some of John O'Hara's finest work. If you enjoyed Grace Metallious's 'Peyton Place' you'll love O'Hara's work which is additionally injected with shrewdly-scribed humor. This is fine 20th Century American literature, better than 99-percent of contemporary works -- it is timeless because O'Hara's characters have existed in every society throughout every era of time.
See my listmania lists for more great recommendations.