Salmonella Men on Planet Porno. Not safe for work. This is quite possibly one of the strangest things I've ever listened to. Some scientists from Earth visit planet Porno, where every species seems to have evolved to have sex with every other species. It doesn't end well. I don't think this one really worked for me - it skips around quite a bit in time, and uses a cast with (to my ear) slightly too similar voices for me to always be sure which character is which. It also felt a bit uncertain in tone, like it wasn't sure whether it was trying to explore a serious point about an alternate route evolution could have taken or if it was just interested in making jokes about the scientists getting off with the local flora.
Bonus weird points for casting a bunch of characters with clearly and obviously Japanese names as a bunch of blokey-sounding Scotsmen.
One. A 15-minute comedy sketch show where each sketch features only one voice. I've found it quite funny, and also genuinely interesting for the number of different framing devices it comes up with for its monologues: telephone calls/voicemail messages are probably the most common frame, but there's one example that's presented as the narration from one of those recorded self-guided museum tour tapes.