Full disclosure, I’m a longtime MSTie (1990, or so). I’m also fond of “alternate history” thought experiments. Put those two things together and you have this topic.
As many fans likely know, during the majority of the years at Comedy Channel/Comedy Central, Frank Conniff was tasked with sorting through the boxes of screener tapes that were sent to Eden Prairie by Nina Hahn. Obviously, a number of tapes were viewed and written off fairly quickly as possibly test subjects. Kevin Murphy once remarked that “twenty films were looked at before a film was picked that would work for the show”.
However, more interesting is that there were a some movies that got past the early rejection phase and made it to the next stage of development. In some cases, these were even listed in upcoming episode guide during the early days of the Usenet Newsgroups. Or, even referenced by cast members in interviews, etc.
Mars Needs Women:
Has been mentioned in several interviews through the years, even by Joel himself. I think this was targeted early on (Comedy Channel).
Was originally scheduled to be Episode 421, per the Usenet, (ultimately replaced with “Monster a Go-Go”), there may have a been a rights issue that prevented it. It has subsequently been mentioned by several cast members (Mary Jo, Frank).
Moment by Moment:
Has been mentioned in several interviews over the years as one that “got away”. Apparently there was a rights issue and it was replaced by another film through the same distributor.
Beyond the Bermuda Triangle:
Originally slated as Episode 623, per the Usenet groups, but dropped. Replaced with The Amazing Transparent Man.
Master Ninja III:
Originally scheduled for the conclusion of Season 6, Episode 624. However, once Frank decided to depart the show, he selected Samson Vs. the Vampire Women for his finale.
The Land Unknown:
Originally scheduled for Season 8. Mentioned during an online discussion with Kevin Murphy in 1996/97. I assuming rights were an issue.
Day of the Triffids:
Mentioned by Mike in a TV Guide interview during Season 8. Also assume rights were an issue here, as well.
This was scheduled to be the MST3K CD-Rom that never saw release.
On this topic, am I missing any?