9 Most Memorable Alternate Universe TV Episodes 

Television science tells us that alternate timelines exist, and that we can visit them at any time. Real-life science, party pooper that it is, tells us that even if alternate universes do exist, it would be impossible to visit or view them in any way. The concept, though, has led to some of the most interesting and entertaining episodes of television ever produced.

Each series that uses it approaches the concept of alternate universes in a different way. Shows like the Jerry O’Connell vehicle from the late ‘90s called Sliders, for example, build their plots around visiting a different alternate reality in every episode.

Television sitcoms like Friends, 3rd Rock From The Sun, Mad About You, and The Big Bang Theory, generally use it to tell what-if stories that stand aside from the regular canon of the show, playing the premise for laughs more than anything else.

Then, of course, there are the genre shows like Doctor Who, Buffy the Vampire Slayer, and others, where alternate universe episodes are most often used to make a point or teach a lesson as is traditional in the genre.

Whether or not you enjoy these episodes, their uniqueness makes them more memorable than the average television story.

Back in the ‘80s, the fictional private military organization known as G.I. Joe fought against an evil terrorist organization that called themselves Cobra. In a two-part episode, the audience got a glimpse of a world where the good guys were gone, and the terrorists had not only won the war, but had fully entrenched themselves in the government.

Worlds Without End sends a small team of Joes into a parallel universe where their teammates were either dead, or in hiding. Cobra has taken over world. The dome of the Capitol building in Washington has been replaced by a cobra’s hood, and Mount Rushmore features the heads of the villainous duo, Cobra Commander and Destro. Things are looking grim.

With a lot of the show’s flashy military action, and the unlikely help of this universe’s Baroness, the Joes are able to turn Cobra Commander and Destro against each other to save this new world before returning to their own.

The alternate universe in this episode gave the writers an opportunity to take the abstract notion that Cobra are the bad guys, and manifest it in a literal way. Without episodes like this, Cobra doesn’t pose a real threat to the world, because the Joes never lose. If there are no stakes, the action can ring hollow.