In case you haven't been following all the collections at archive.org, here's an article that showcases some amazing science fiction episodes from the early 1950's Dimension X radio show. Fifty half hour shows are available at the archive.org site which should be a good TV replacement for a week or two.
From the site:
Dimension X made its mark by adapting short stories by acknowledged masters of the craft: Isaac Asimov, Ray Bradbury, Robert Heinlein, and even a non-genre-bound literary mind like Kurt Vonnegut. All of these world-creators knew well the value of imagination, and radio, in its way, stood then and remains today the most evocative, imagination-driven medium of them all.
(Score: 2) by Theophrastus on Wednesday June 11 2014, @10:11PM
Some of these are really wonderful - thank you for posting this source!
My old man had some of these on reel-to-reel, which i listened to as a kid; several of these have plots that are damn close to later TV scripts. As one example, i recall that "Mars is Heaven" (Dimension_X_1951-01-07__33_MarsIsHeaven.mp3) has many of the plot points of star-trek/orig-series "The Cage" (later "The Menagerie"). Also some of the Outer Limits plots sync right up. I think all the old TV scifi series producers must have listened to "Dimension X".