Lux Radio Theater
The Lux Radio Theater was the drama on the air, with top stars recreating popular films. It ran from 1934 until 1955.
John Dunning wrote in On the Air: The Encyclopedia of Old-Time Radio:
The Lux Radio Theater was the most important dramatic show in radio. It had the biggest stars, the highest budgets, the most acclaim. It had a full hour and, during its heyday, Hollywood's most prominent film director as host. It had an austere sound, almost solemn. As Tune In noted in 1943: when Cecil B. DeMille opened the broadcast with his weekly "Greetings from Hollywood, ladies and gentlemen," it was almost sounded like "This is God, speaking from heaven."
Here is a sample of the online episodes currently available at The Old Time Radio Fan: