TV's Best Alternate Reality Episodes, Ranked: Buffy, The O.C., Community, Supernatural, The Arrowverse And More

Move over, bottle episodes and musical installments. We're paying tribute to another time-honored TV tradition: the alternate reality episode, in which a show takes a brief vacation from the norm and presents a world where the characters' lives turned out quite different — often for better and for worse.

In honor of this Tuesday's dream world All Rise, TVLine has ranked 15 of the best alt universe installments from some of our favorite dramas, comedies and soaps. Our picks range from seemingly idyllic fantasy scenarios*, courtesy of Supernatural and Arrow, to a truly bleak nightmare reality that even the slayer can't save. (*With the good, comes the bad.)

There's plenty of fun to be had, too, with Family Guy's multiverse of shenanigans, Community' game of "what if...?" and Family Matters' role reversal. And of course, what would an alternate world be without some amusingly unexpected romantic pairings like two Friends hooking up or The O.C.'s Sandy Cohen being married to... Julie Cooper?!

You'll also find that the variety of out-there scenarios is matched by the different devices — aliens! comas! wish-granting demons! — that the series used to send their characters spinning off into the land of the delightfully bizarre.

Review our ranking of distinct alternate-reality episodes below to see which show topped the list, then hit the comments to share your favorites and any selections that didn't make the cut!

NBC's criminally underrated sitcom went way overboard with the gleefully absurd Season 4 finale, which sees the WNYX crew playing passengers on the doomed Titanic. (This was May 1998, you see, when the nation was still gripped by Titanic fever.) We can blame the ship's demise on whoever put bumbling Matthew on iceberg watch, and Phil Hartman is fantastic as a pompous aristocrat — which is bittersweet, as Hartman was killed just two weeks after this episode aired, making this his final NewsRadio appearance.

Season 5's "Reckoning" was more a "do-over" episode, and its "alternate" reality wound up sticking (sorry, Pa Kent!). Season 7's "Apocalypse," meanwhile, propelled Clark into a fully alternate existence — be careful what you wish for while clutching a cosmic talisman! — where he had never arrived on Earth. A stranger to Lois, Chloe et al, Clark discovered that cousin Kara was doing the bidding of President Lex Luthor, who had Brainiac pulling his strings. The episode scattered some fun Easter eggs (Clark in eyeglasses! Jimmy's bowtie!) and a nuclear war was averted, but the coda (Clark went back in time to safely launch his infant self into space from Krypton?!) was a bit wobbly.

After blowing up at Steve for breaking her expensive Christmas gift, Laura wishes that Urkel could understand what it's like to be her. A guardian angel grants her wish with a twist: She must walk a mile in his shoes as Laura Urkel, while Steve becomes a member of the Winslow family. The episode is a fun reversal of roles as she takes on Steve's dorky persona, down to the nasally voice and chronic clumsiness. But in true Family Matters fashion, the swap also comes with a valuable lesson. When Steve yells at Laura in the same way she did earlier, Laura learns how hurtful her reaction was and even gets a second chance to handle the situation with a cooler head.

After Ryan and Taylor fall off a ladder, they enter a very meta coma world where Taylor explains to Ryan that they must be in an alternate universe (duh!) where he never came to live with the Cohens. As a result, Newport mayor Sandy and a cold-hearted Kirsten are now divorced and remarried to Julie and Jimmy, respectively. But Julie's also getting it on with Chris Pratt's Chester, aka the fiancé of Summer, who's a vapid bimbo. And Seth? Let's just say if you thought he was whiny before, that was nothing. The bizarre hilarity is offset when Ryan mistakenly thinks Marissa is still alive in this world, only to learn that she died of an overdose in Tijuana. In the end, the touching revelation that he could never truly save her and actually gave her three extra years to fall in love and graduate helps Ryan finally move on from Marissa's death.

Few TV series have elevated the ubiquitous "It's a Wonderful Life homage" gimmick to such high artistry as the late, great NBC soap. In 1989, an angel played by special guest star Ronnie Schell escorted A Martinez's broken and forlorn Cruz Castillo through an alternate version of his life in which he had never been born. Infused with dark humor and featuring sumptuous visuals, the episode deservedly earned SB a then-unprecedented third consecutive Emmy for Outstanding Daytime Drama series.

On Cordelia's 21st birthday, a vision renders her unconscious and puts her into a coma during which an otherworldly guide offers her the chance to experience her Los Angeles life as if she'd never met Angel — and she takes it. Alt-Cordy is thriving; she's an Emmy-winning actress. But in this reality, Wesley has lost an arm and Angel is about to lose his mind from the visions he inherited from Doyle. So Cordy selflessly takes them back, choosing evil-hunting in obscurity — albeit with a half-demon upgrade to help her weather the visions — over the seriously fabulous life of a sitcom star. (And make no mistake: That fully produced intro for Cordy! was truly fabulous.)

The Season 3 Christmas episode finds a grumpy — some might say Scrooge-like — Maddie wishing she'd never decided to keep Blue Moon Investigations open. So a guardian angel shows up and changes her reality, It's a Wonderful Life-style. At the alt-agency, Agnes is a cutthroat businesswoman with no time for love! David is getting married to model Cheryl Tiegs but is despondent about life! All tropes aside, the hour is a lovely showcase for Cybill Shepherd, Mean Agnes is a hoot and the happy ending features a pretty great kiss between David and Maddie. God bless us, everyone!

This fan-favorite episode finds Stewie giving Brian a tour of various universes, and in typical Family Guy fashion, each is more twisted than the one preceding it. There's the universe where Meg is hot, and the one where everybody suddenly has to poop right this minute — but none will haunt us like the Disney universe, which dramatically changes its tune when Mort Goldman shows up. Let's just say that Family Guy really enjoys playing up certain unflattering rumors about Walt Disney, and we'll leave it at that.

After spending 135 episodes with the Central Perk crew, viewers had earned the right to a little Friends fan fiction. And that's exactly what they got in this hilarious (and extremely hypothetical) two-parter. A soap-obsessed Rachel cheating on her husband with not-fired Days of Our Lives star Joey? Ross attempting a threesome with Carol and Susan to save his marriage? Phoebe as a stressed-out, chainsmoking stockbroker? All incredible scenarios. And while Monica's iconic fat suit certainly hasn't aged well since this aired more than two decades ago, at least the episode proved that she and Chandler were destined to get together in any timeline — even if he mistook her for a couch the first time they tried to have sex.

Back when the Arrowverse was firing on all cylinders, we got this third installment in the four-part "Invasion!" crossover event — which also happened to be Arrow's 100th episode. In it, Oliver, Diggle, Sara, Thea and Ray Palmer had been abducted by the extraterrestrial Dominators and implanted in an alternate reality where The Queen's Gambit never took that fateful trip. As a result, Oliver instead was living at the Queen mansion and readying for his and Laurel's wedding day when he began experiencing "flashes" to his actual life, all as Felicity, Curtis and Rory, back on Earth, teamed with The Flash's Cisco, Supergirl's Kara and Legends' Nate to find their missing friends. The Easter eggs were superfun (Diggle as The Hood!), while a climactic group fight between the "awakened" Oliver & Co. and incarnations of Deathstroke, Damien Darhk and Malcolm Merlyn was a total blast.

The Season 3 opener finds Barry Allen in an alternate reality in which his mother is still alive after traveling back in time to stop the Reverse Flash from killing her. But Barry's idyllic new life comes at a cost: Joe and Iris' relationship is fractured; Cisco owns S.T.A.R. Labs but hates crimefighting; he's losing his memories the more he uses his speed; and Wally is unable to heal himself after getting injured in a fight. The beauty of this episode is that even after Barry goes back in time to make things right — allowing Thawne to kill his mother — it still doesn't fix everything. He returns to a timeline that has changed, and now our hero is forced to deal with the consequences of his actions.

When a Djinn traps Dean in a reality where his mother was never killed (and his dad died peacefully in his sleep), the emotional gut punch is a whopper that makes for one of the show's most impactful episodes. Suddenly, Dean seemingly has everything that he's ever wanted, but things slowly start to unravel as he realizes that all of the people that he and Sam saved are dead in this world. And in another heartbreaking change, Dean's relationship with his brother (who's engaged to Jessica, aka Sam's girlfriend from the pilot episode!) is practically nonexistent. In the end, Dean is forced to make the tough decision to kill the Djinn and come out of this so-called "dream," but for a brief moment, it was a beautiful fantasy.

It's truly a "be careful what you wish for" scenario in this classic Season 3 installment, in which Cordelia — yes, Cordy's at the center of this alt reality episode, too — unknowingly makes a wish to the demon Anya that Buffy Summers never came to Sunnydale. In the nightmare universe, the town is overrun by vampires like Xander and Willow, who are now moody, leather-clad bloodsuckers. Plus, The Master is alive, Angel is a prisoner who's tortured by Willow, and students die so frequently that the school has a monthly memorial service. When a world-weary Buffy finally does arrive, she ends up getting her neck snapped by The Master! It's bleak and dark, but an extremely tantalizing "what if...?" episode.

The Darkest Timeline is established in one of the all-time great Community episodes, in which the study group gathers for Troy and Abed's housewarming party. A Yahtzee! dice is used to determine who has to get up to retrieve the pizza and inadvertently sets up seven different scenarios. That includes the terrible, horrible, no good, very bad Darkest Timeline wherein Pierce suffers a fatal gunshot wound, Shirley becomes a drunk, Annie gets locked in a mental ward, Jeff loses his arm in a fire and Troy loses his larynx after he tries to destroy a flaming troll doll by eating it — all because Jeff rolled a one.

Here, we have the O.G. of alternate reality TV: Kirk and the Enterprise crew cross paths with themselves in a parallel universe where they are all evil, sadistic minions in the bloodthirsty Terran Empire. The episode's introduction of a "mirror universe" inspired decades of mind-bending sci-fi to come, and it's a lot of fun to watch the Trek cast play "evil twin" versions of themselves. Oh, and Mirror Spock's goatee? Iconic.