The LEVIATHAN CHRONICLES is a full-cast scifi audio drama with some seriously high production levels. Creator Christof Laputka and his team of audio ninjas just dropped their 25th episode, so there's plenty of content to see if the story is up your alley.
This sounds like scifi, but I'd say its more fantasy with tech. Crazy, over-the-top story. Check it out and see if you dig it.
The website is also pretty cool. These guys go all-out for the eye- and ear-candy, and clearly want to give their listeners a professional experience.