In Ace Lightning, not only are the video game characters stuck in the real world, a few human characters also get trapped in the video game over the course of the series.
Angel has an episode where Cordelia ends up trapped in Pylea and quickly goes from being a slave to becoming queen. Naturally, Angel and the gang soon follow to rescue her. At the end of the adventure, they end up overthrowing the ruling demon priests and freeing the human slaves. Fred was stuck there, too, for five years before the others arrived, though she didn't do nearly as much as Cordy.
Doctor Who: Rose is trapped in a parallel world, but returns with knowledge of "the Darkness" threatening to destroy the multiverse (as her universe is ahead of ours). She is then forced to remain in her parallel world to take care of the clone-Doctor, despite wanting to stay with the real one. Former boyfriend Mickey, however, decides to leave the parallel world for his old one.
As expected, this is the central premise of Emerald City. However, it's also revealed that Jane, the lead engineer on the experiment that threw her, Dorothy's mother, and the Wizard into Oz, is also trapped there. In fact, Dorothy was born in Oz, but her mother managed to get back to our world with her and left her with foster parents.
Farscape, where Crichton travels through a wormhole to another part of the universe. His overriding goal for most of the series is to get back to Earth...but when he finally does, he leaves very shortly to go back to the other side of the universe. He later returns and makes it impossible for himself to ever go back in order to protect Earth from the bad guys. John, being John, makes many a reference to The Wizard of Oz in relation to his situation. Title of the episode when they really go to Earth: "Kansas".
In Season 3 of Fringe, Olivia is trapped a good deal of the time in an alternate universe. Peter has been trapped in another universe since he was seven years old.
In Kyle XY, Josh frequently suggests that Kyle is an alien from another world (although this is later subverted when Kyle's true origins are revealed).
Loki features this trope, as Loki and Sylvie eventually get marooned on the moon Lamenis in the year 2077 that is set to explode. They spend the whole episode trying to find a way off the planet, but their attempts are in vain. Seconds before they die, the Time Variance Authority rescues them.
And the sequel Ashes to Ashes (2008), which resolves the mystery: note Nothing is overtly stated about what's going on, but the central mystery is resolvedThe world is a purgatory for select dead police officers.
The American version is much less ambiguous. note On the bright side, because it concluded itself after only one season, it provided the writers of British Ashes to Ashes a lesson on what NOT to do.
The island of Lost is sufficiently weird that a case could be made.
In the first episode of MythQuest, Matt Bellows gets trapped inside a mythical world with a trickster god. His children accidentally (and later deliberately) get trapped in myths when they go to look for him.
Once Upon a Timeloves this trope. The main one involves an inversion, with various characters from a fairy-tale world trapped in our world, but throughout the series different people keep getting stranded in different worlds and have to find a way out.
The premise of the series Pirate Island is that three children are trapped in a video game.
Likewise Quantum Leap, where Sam continually leaps into the bodies of various people between when he was born (1953) and the show's present of 1999.
Sliders: The Sliders have a device that can take them between worlds, but it malfunctions, and they're stuck going between worlds without any control in the hope of eventually finding home.
This happens a lot in the Polish/Australian children's series Spellbinder. Paul gets trapped in the Spellbinder universe, Kathy's family gets trapped in the Land of the Dragon Lord, and Mek and Kathy end up trapped in first the Land of the Immortals and then the Land of the Moloch.
Season 1 of Stargate Atlantis — trapped in the Pegasus Galaxy. This is a variation, because the expedition went to Atlantis knowing full well that they might be stranded there.
Stargate Universe takes this tack as well, stranding the heroes on a space ship headed away from known space. They are billions of light years away from home and if they could control the ship, the journey would take millions of years. They don't have enough power to dial home and dialing IN from the Milky Way needs a special kind of planet but even then, a small mistake in the calculations will cut off the supply line permanently via an Earth-Shattering Kaboom. This happened in the first episode. Later, it was revealed that the Lucian Alliance found another planet which the SGC attempted to capture; the Alliance however activated the gate prematurely and this planet blew up as well.
This is the story arc of Season 1 of Stranger Things. Will gets trapped in the Upside Down dimension by the Demogorgon, but is nevertheless able to communicate with his family and friends via Christmas lights and Eleven's psychic powers. Eventually, Hopper and Joyce come to his rescue in the season's finale.
Supernaturalloves episodes that transport the Winchesters to alternate universes and timelines.
In Season 2, Dean is transported by a Jinn into a world where his mother never died and he and Sam never became hunters. It turns out it was all part of the Jinn's method to feed on his victims and exists only in Dean's mind.
In Season 4, Dean and Sam work normal office jobs with no memory of being monster hunters or each other. This world turns out to be our universe, just one where an angel wiped Sam and Dean's memories.
In Season 5, Dean finds himself in a Bad Future, where Sam has said yes to Lucifer, he has become a hardened Jerkass willing to sacrifice his friends and a Zombie apocalypse has ravaged the world.
In Season 6, The boys find themselves in an alternate world where their lives are a tv show and they are mistaken for the actors who play them.
In Season 6, they find themselves in an alternate timeline where the Titanic never sank, they drive a Ford Mustang, Ellen and Jo are alive and Celine Dion is a destitute lounge singer.
Later seasons feature Charlie visiting Oz, the alternative dimension that inspired L. Frank Baum.
Later seasons also feature an Apocalypse World where Sam and Dean were never born.
A Season 13 episode features the Winchesters and Castiel being transported into the animated world of Scooby-Doo.
The Time Tunnel — two guys trapped in the past (or occasionally the future).
Zapped is a British TV series revolving around a temporary office worker who receives a mysterious amulet which teleports him to Munty, a place in a fantasy universe controlled by a police state. The rest of the series revolves around his attempts to get back to the real world.
