Both the old and new series are heavily inspired by series creator Glen Larson's Mormon faith, making it effectively The Book of MormonIN SPACE!
Hmm...the twelve tribes colonies, originated from Eden Kobol, was forced to move from their homeland to find a promised land Earth that only was known from legend, all due to the actions of a certain man, who after receiving visions and power from a higher being, eventually become the founder and leader of Judaism Christianity a monothestic religion and preach about grace, and after wandering around the desert space for forty four years, manage to arrive on a lush green place planet that is eventually OUR Earth, all according to the plan of the higher being. Hmm, sounds like a familiar book...
The re-imagined series gave us the episode "The Captain's Hand" = Crimson TideIN SPACE!
With the revival of serial-formatted TV such as 24 and others, rather than episodic tales, the Re-imagined Series and J.J. Abrams's Lost were can't-miss-an-episode shows at the time. The subject matter and Mind Screw plots between these two shows were too similar for some fans, jesting that the new BSG was "LOST:IN SPACE!"
The Buck Rogers in the 25th Century episode "Space Vampire" is Dracula...In Space, complete with a wrecked ship with a ship's log that documents the deaths of the crew and a passenger named William Helsing from "New London"
The Charmed episode "The Magic Hour" was Ladyhawke [-IN CALIFORNIA-! -WITH GOOD WITCHES]!
The episode "Dead Man Dating" was GhostIN SAN FRANCISCO, WITH WITCHES AND DEMONS!
Parodied on The Daily Show during a short in which Jon Stewart, Steve Carell and Stephen Colbert are TV producers trying to come up with a new reality show. At one point, Colbert complains that "Every pitch [Stewart] makes is just one of mine with the words IN SPACE added to the end."
Half of all Doctor Who episodes ever are "Hammer Horror/Classic Literature/Contemporary Movie/Greek Mythology etc., WITH ALIENS!" Doctor Who author Ben Aaronovitch once said that "Talent borrows, genius steals, and Doctor Who authors get it off the back of a lorry, no questions asked."
The Doctor Who episode "Voyage of the Damned" was The Poseidon AdventureIN SPACE! It's even lampshaded, since the space ship is appropriately named The Titanic.
The Duck Factory featured a young Jim Carrey tasked with rebooting a stale cartoon show. After finding he'd just proposed killing off the producer's favorite character, he notes the producer's office decor and saves the day by adding, "did I mention this all happens IN SPACE?"
Far Out Space Nuts is a Saturday morning Gilligan's IslandIN SPACE! Complete with Bob Denver playing Gilligan's Expy. "I said LUNCH, not LAUNCH!"
Farscape, with varying degrees of delight, made several such episodes. Possibly the most memorable is the one where, locked inside his own mind, Crichton turns his existence into a Looney Tunes cartoon, with a lot of reference to the Wile E. Coyote/Roadrunner cartoons.
For that matter, the entire premise of the show is really just Alice in Wonderland... in SPACE.
Firefly's premise is the American Civil War...IN SPACE!
Mighty Morphin' Power Rangers and Power Rangers Zeo were aversions, and not just because they were the originals. Production took the seasonal themes from Super Sentai such as dinosaurs, Eastern mythology, and ancient world cultures (or something) and downplayed them so that things were kept as generic as possible - so stuff was recycled, but not IN SPACE! Mighty Morphin' Season 3, however, went a fair way towards being Power Rangers AS NINJAS!
Power Rangers in Space: Despite the name, averted! The move to outer space brought a lot of changes to the status quo, such as more complex villains and mostly abandoning the City of Adventure setup in favor of searching alien planets for their kidnapped mentor. Some of these things were then recycled into future seasons, others weren't.
Gene Roddenberry described James T. Kirk as a space-age Horatio Hornblower in the book The Making of Star Trek (1968).
The Star Trek episode "Balance of Terror" is the 1957 WWII submarine movie The Enemy BelowIN SPACE! Even the bearing of the unidentified initial contact and the captain's maneuvering orders to the helm are copied nearly verbatim. The Romulan ship is cramped and has lots of piping and conduits in all background scenes. The Enterprise's phasers act like depth charges, and at one point the Enterprise and the Romulan ship both go to silent running, fearing to talk loudlylest the other vessel hear them.
The Romulans in this episode were The Roman EmpireIN SPACE!, as exemplified by Mark Lenard's dignified Centurion character. They didn't stay that way, though. Compare the Romulans in the Star Trek reboot movie.
The much-maligned Star Trek: Deep Space Nine episode "Meridian" was, as admitted by producer Ira Steven Behr, BrigadoonIN SPACE! Recalling this idea at a later date, Behr admitted: "I am a moron."
The original concept for Deep Space Nine (before they shifted the location from a Federation colony planet to a space station after J. Michael Straczynski pitched Babylon 5 to Paramount) would have been Star TrekON LAND!
The episode "Starship Down" is basically Das BootIN SPACE.