X Minus One was the best of the full-cast science fiction radio shows of the 50s (episodes like “Star Bright”, “The Parade”, and “Field Study” are forever etched in my memory) but there were several others - I recommend the Relic Radio Science Fiction podcast (https://www.relicradio.com/otr/home-2/science-fiction/) for a sampling of them.
My favorite science fiction radio, though, is Michael Hanson’s Mind Webs. You can listen to all of the episodes at the Internet Archive (https://archive.org/details/MindWebs_201410) & I compiled a list of my favorite episodes to guide you on your journey at https://blog.robador.com/2015/04/the-best-of-mind-webs/. Not full cast, but great stories told well with good music. They even made some new episodes a couple years ago before Michael Hanson died.