Given the constant churn of sci-fi reboots and reinventions, you could be forgiven for assuming there’s no classic science fiction that hasn’t been remade again and again with diminishing returns. However, you may be shocked to learn that there are some truly classic sci-fi franchises which remain basically untouched in modern cinema and television.

Here are five sci-fi franchises that were once incredibly popular, but have fallen by the wayside in modern cinema and television, either totally ignored or stuck in development Hell.

For this list, we’re looking for sci-fi franchises with past TV or film success, and which have elements that could conceivably make them popular if rebooted today. We’re also excluding any franchises with new entries in active development, including Forbidden Planet, Blake’s 7 and Neuromancer.

Logan’s Run

Starting in 1967 with the sci-fi novel from William F. Nolan and George Clayton Johnson, Logan’s Run depicts a society where a strict ‘maximum age’ is maintained via the ritualistic killing of citizens (varying between 21 and 30 depending on the iteration.)

The story follows a ‘Sandman’ named Logan, whose job is to track down and kill anyone who attempts to escape euthanasia, though he eventually becomes sympathetic to ‘Runners’ and attempts to escape himself to the legendary ‘Sanctuary.’ Despite a trilogy of novels exploring this hard sci-fi universe, there’s only been one movie adaptation – 1976’s Logan’s Run, directed by Michael Anderson, which itself spawned a spin-off TV series of the same name.

Multiple other adaptations have been attempted, with big names including Alex Garland, Bryan Singer, Simon Kinberg, Ryan Gosling and Rose Byrne reportedly attached, but the various projects have either been canceled or continue to languish in development Hell.

That’s a shame, because Logan’s Run has a compelling aesthetic of a pristine, hippy-tinged utopia built on rotten foundations, and engages with themes of intergenerational conflict which have never been less than relevant.

The Prisoner

After dramatically resigning from his post, an unnamed intelligence agent wakes up on an island prison modeled after a pristine small town and known only as ‘The VIllage.’ Stripped of his name, ‘Number Six’ attempts to escape, while the technologically advanced forces running the Village attempt to trick, bribe, blackmail and torture him into revealing details about the assignment that caused him to quit.

The Prison has a unique retro-futuristic aesthetic, set in a disturbing mockery of suburbia where members of the Village wear preppy blazers and ride around on bicycles while under constant, aggressive surveillance. The show’s standout creation is Rover – a gigantic, featureless ball which chases and suffocates anyone who tries to escape.

The Prisoner is the ideal property for a post-Lost world where questions-within-questions are a proven way to build a loyal fanbase. Pretty much everything that happens in The Prisoner is one type of mystery or another, from the question of who is running the Village to whether they really want information from Number Six, or if the whole Village is just a testing ground for experimental interrogation techniques.

The franchise most recently returned in a 2009 remake by AMC which spectacularly failed to recapture the tone or aesthetic of the original, despite Ian McKellen playing the Village’s villainous overseer, Number 2. There were even rumors that Christopher Nolan would direct a trippy movie based on the series that ultimately came to nothing.

Invasion of the Body Snatchers

Beginning with Jack Finney’s 1955 novel The Body Snatchers, this franchise focuses on a hidden alien invasion where regular people are replaced by exact duplicates grown in giant pods. Film adaptations in 1954, 1978, 1993 and 2007 updated the story to reflect the unique paranoia of each era (here’s our list and rating of every Invasion of the Body Snatchers adaptation.)

The nightmarish scenario of the people in your life gradually being replaced and turning against you is a perennial favorite, and the franchise is begging for some kind of anthology show where different people deal with the invasion under varying circumstances. However, it’s coming up on twenty years since the last official attempt – Oliver Hirschbiegel’s The Invasion, starring Nicole Kidman and Daniel Craig.

What makes this worse is that some gigantic modern hits are arguably inspired by the franchise, from Vince Gilligan’s Pluribus to Jordan Peterson’s Us and the butterflies from James Gunn’s Peacemaker. It’s past time the original got in on the proven success of its own premise, especially due to the unique aesthetic of its insidious alien pods cooking up human replicas.

Soylent Green

The Soylent Green franchise started out with 1966’s sci-fi novel Make Room! Make Room! from Harry Harrison, but was popularized by the 1973 movie from Richard Fleischer, which took significant liberties with the story.

The franchise is set in a near future, where overcrowding and resource scarcity are causing dystopian conditions, and follows a detective investigating a suspicious death which exposes the dark truths underlying this chaotic society. The movie added the iconic reveal that the miracle food product used to sustain the population, Soylent Green, is secretly made of dead bodies, ending with the iconic line, “Soylent Green is people!”

While the cannibalistic twist is what made the franchise famous, the key themes of corporate inhumanity, urban deprivation and environmental collapse would doubtlessly find an audience today. Remakes and even a sequel have been attempted in the past, but this iconic franchise has been languishing for fifty-three years without a new entry of any kind.

Captain Scarlet and the Mysterons

Captain Scarlet and the Mysterons depicts a vicious cold war between Earth and a mysterious group of aliens known as the Mysterons. The aliens possess the ability to construct exact duplicates of anyone they kill, creating a sense of paranoia that permeates the entire franchise.

The titular hero is one of the aliens’ duplicates on whom their brainwashing fails, granting him a powerful healing factor and turning him into the ideal agent to face down their malevolent plans, under the command of intelligence agency Spectrum.

Captain Scarlet and the Mysterons is unique on this list in being aimed at children, but in a world where Barbie, Teenage Mutant Ninja Turtles, Powers Rangers and He-Man can spawn blockbuster movies, this 1967 TV show more than deserves a chance at an adult audience, even if that means leaving its electronic marionettes behind.

The show has an amazing aesthetic, from the multi-colored agents of Spectrum to the Mysterons, who are never seen on-screen, but make their presence known through their glowing sigil and taunting, croaked messages, which always begin, “This is the voice of the Mysterons…”

Created by Gerry and Sylvia Anderson, the franchise attempted a CGI rebirth in 2005’s New Captain Scarlet, but it would benefit from a live-action approach aimed at an older audience. The aesthetic and sense of paranoia have aged well, as has the franchise’s sense of moral grays (the Mysterons only attack in the first place because humanity mistakenly attacks their city on Mars.)

Those are the five sci-fi franchises we think are begging for a modern reboot or reimagining, from the anthology potential of Invasion of the Body Snatchers to the disturbing topicality of Soylent Green. Let us know in the comments below what other classic sci-fi franchises need to make a modern comeback, and what form you think the entries on our list should take.