"Suspense" represents some of the best OTR from the Golden age of radio.
Here are three favorites, the first stars Vincent Price, the second stars Orson Welles and the last is adapted from a 1938 short story by Cornell Woolrich.
Suspense - 1956-11-11 - Three Skeleton Key
Suspense - 1945-09-02 - The Hitchiker - Orson Welles
Suspense - 1949-03-10 - Three O'Clock
The first one is better known as "Rats", and after listening you will understand why...