3. Buffy the Vampire Slayer – 'Once More, With Feeling'
Six series in, and the inhabitants of Summerdale let their hair down and got their larynxes out, as Buffy and co bellowed show-stopping numbers to varying degrees of success.
As self-referential plot-points in themselves, creator Joss Whedon's insanely catchy melodies are integral to the narrative, as the bewitched townsfolk finds themselves crooning knowing half-truths and personality traits to all and sundry (well, sundry, mostly).
The best episode of Buffy the Vampire Slayer? Yeah, we're happy with that.
Ever been watching your favourite telly show and suspected that the writers had decided to... how to put this politely... let their hair down that particular week?
Some of the biggest TV series ever made feature one episode that's a total anomaly, sitting outside the usual order of things by embracing a new style, genre or format for one week only. Looks like we all go a little mad sometimes...
1. Dallas – 'Conundrum'
As a soap, Dallas was hardly on kissing terms with reality, but its writers went full-tilt fantasy for the final episode of its original TV run.
With that stetson-rocking reprobate JR Ewing on the point of suicide, the series goes It's a Wonderful Life when an apparently angelic spirit named Adam (played with campy relish by Joel Grey) shows the crooked oil tycoon what life for everyone he knows would have been like if he'd never existed.
So far, so heartwarming, except in the last few moments it's revealed that Adam is – drumroll, please – the Devil (and oh yes, they even go for the blood-red eyes), who then, as JR pulls the gun to his temple, cries, "Do it!" Cue end titles.
2. Bergerac – 'The Dig'
A ratings-conquering show for the BBC in the 1980s, Bergerac headlined housewives' favourite John Nettles as a dogged but dull Jersey-based 'tec investigating everything from gangland murders to money-laundering to missing persons.
All pretty standard crime drama larks, but, once in a while, the show would properly wig out. It dipped its toe into horror waters a few times over the years, but 'The Dig', from series eight, was Bergerac at its most brazenly bizarre.
There's more than a touch of MR James in this eerie tale of archaeologists disturbing an ancient Viking warrior's tomb, even to the point of having Jim Bergerac being attacked by an invisible raven (no, really).
The series normally had some kind of stodgily rational explanation at the end of its horror episodes, but 'The Dig' sticks bravely to its supernatural guns. This kind of thing never happened in Midsomer Murders.
3. The Sopranos – 'Pine Barrens'
The Sopranos rarely ventured beyond the streets of New Jersey, or indeed turned its gaze away from Tony Soprano himself. So, from a distance, this third season episode looked a bit throwaway, a chance for the main players to take a vacation, while the supporting actors stepped into the spotlight.
Centring on Paulie and Christopher as they hunt down a Russian mobster in the snowy plains of Pine Barrens, it feels more like a quirky Coen Brothers comedy than a glossy mob flick, which ain't too much of a surprise seeing as it was directed by Coen Brothers favourite (and future Sopranos regular) Steve Buscemi.
4. Family Guy – 'Brian and Stewie'
With not a single cutaway gag or musical score, this two-hander featuring everyone's favourite dog-and-baby duo is a slow-paced departure from the series' usual frenetic gallop.
Set within the confines of a bank vault, this 150th special was nevertheless still firmly Family Guy-flavoured, what with its vomit-eating, self-mutilation and a drunk, gun-wielding 1-year-old. With sole voice talent contribution from series creator Seth MacFarlane himself, there can't have been many other TV programmes where one main character munches down the other's poo.
5. The X-Files – 'X-Cops'
The X-Files was never a series shy of screwing with the formula once in a while. There are plenty of format-fudging episodes to pluck from this series – the black and white 'Post-Modern Prometheus', the giddily self-referential 'Hollywood AD' or the dual-perspective scarefest 'Bad Blood' – but this seventh season episode is possibly The X-Files at its most wilfully odd.
Penned by Breaking Bad main man Vince Gilligan, it's presented as an episode of Fox's reality series Cops, with a TV crew following a loving-it Mulder and a get-that-camera-away-from-me Scully, as well as officers from the LAPD, in their investigation of a rampaging werewolf.
6. Farscape – 'Revenging Angel'
For sheer balls-out audacity, this semi-animated Looney Tunes pastiche from the third season of 1990s sci-fi fave Farscape takes some beating.
Using the old "coma-induced" conceit, the plot pretty much abandons reality for cel-shaded shit-kicking and familiar cartoon tropes (an anvil is a dropped on someone's head ala Wile E Coyote, Crichton re-draws Aeryn in a callback to the classic Warner Bros. short 'Duck Amuck', etc).
Community would try something similar with the episode 'GI Jeff', but Farscape got there first.
7. Star Trek: Deep Space Nine – 'Far Beyond the Stars'
The cast of Star Trek: Deep Space Nine shed their Starfleet cossies and outer space prosthetics for this 1950s-set meta-strum about Benny Russell, a black science-fiction writer (played by Avery 'Captain Sisko' Brooks) who writes a short story titled – you got it – Deep Space Nine.
So, the question is, is Benny a character within the head of Captain Sisko or is Captain Sisko a creation of Benny Russell? A hundred Media Studies lecturers just squealed with excitement
8. Buffy the Vampire Slayer – 'Once More, With Feeling'
Six series in, and the inhabitants of Summerdale let their hair down and got their larynxes out, as Buffy and co bellowed show-stopping numbers to varying degrees of success.
As self-referential plot-points in themselves, creator Joss Whedon's insanely catchy melodies are integral to the narrative, as the bewitched townsfolk finds themselves crooning knowing half-truths and personality traits to all and sundry (well, sundry, mostly).
