The two most famous Dallas storylines were the shooting of JR and Bobby's much-mocked shower scene. Nick Richards and Judy Rimmer recall the glossy soap's top turning-points.
In the pre-internet, pre-streaming and pre-satellite world of the early 1980s, a TV plot could captivate the nation. Cast your mind back almost 40 years – were you hooked on the biggest global soap plot of all time?
With just three TV channels back in 1980 a massive soap like Dallas could enthral a big chunk of the nation and the glitz and glam of Southfork was a great bit of escapism for millions of us.
In spring 1980 the final episode of season three of Dallas, A House Divided, concluded with the shooting of JR Ewing by an unidentified perpetrator while he working in his office.
Over the summer months, ahead of the start of season four, global speculation mounted on who had pulled the trigger – remember that back in the early 1980s there were an estimated quarter of a billion viewers worldwide regularly tuning in for their dose of action between those squabbling Texan oil barrons.
Pretty much the whole cast were suspected of pulling the trigger, including Sue Ellen's lover Dusty Farlow, Sue Ellen herself, JR's rival Cliff Barnes and even good old Miss Ellie.
Producers were keen to add a sense of mystery – and mischief – to the event and filmed multiple endings with different characters firing the gun. It was thought even the cast didn't know who would be framed for JR's killing.
The arrival of the video tapes containing the crucial episode Who Done It even made the main BBC 9 O'Clock News, with presenter Jan Leeming telling viewers on the evening of November 21, 1980 that the tapes had been flown into the UK ahead of the following night's show.
They were escorted into the country by an American security guard and kept at a secret location overnight to ensure nobody on these shores took a sneaky peak at them. Only after the show had been broadcast in America were the tapes given to the BBC.
On the evening of November 22, 1980, 21.6 million UK viewers sat down to watch the drama unfold as JR's attacker was revealed.
Over in the US, between 83 million and 90 million people watched it.
It was the most watched television episode in American history and has only since been surpassed by the finales of M.A.S.H in 1983 and Cheers in 1993.
What a shower that scene turned out to be
Six years after JR's shooting came the moment which was described as 'the most famous shower scene since Psycho' by Associated Press - or should that have been 'infamous'?
In the 1986 season finale, Pam woke up to hear a shower running, and expected to see her new husband Mark. But instead, she found the man in the shower was Bobby, who had died in a car crash a year earlier.
Bewildered viewers were left in limbo until the next season, wondering whether Bobby had secretly survived the accident, faked his death, or had a doppelganger.
Or whether, as it turned out, the previous season had all been a bad dream.
The aim was to restore falling ratings by bringing back Bobby. But many viewers were not impressed, losing all faith in the show from then on, as all continuity was lost.
Proving to be the show's second most famous storyline after Who Shot JR, the scene has since been endlessly mocked, including a classic Spitting Image sketch,
Margaret Thatcher woke up to find Edward Heath in her shower - discovering that he was still prime minister and she had only dreamed of being in power. She then stabbed him, Psycho style.
The Simpsons also had a shower scene episode where Smithers dreamed that Mr Burns had not really been shot. Victoria Principal and Patrick Duffy even filmed a live action spoof of the scene for an episode of Family Guy.
And, when Dallas returned for a revival series in 2012, the advertising showed several characters wearing towels in a shower, with the tag line, 'They're back, and no, you're not dreaming.'
Knots Landing was addictive daytime TV - EDP editor David Powles recalls the show
Maybe I was what you'd class as a Mummy's Boy. Perhaps I was just a little bit strange. Perhaps it was an addiction.
But for one reason or another, as a teenager growing up in the early 90s, I had a slightly unsettling interest in American soaps and comedies.
It started fairly reasonably, with the popular soap/comedy crossover Roseanne, which all of my family enjoyed watching together during the days when not only was it actually funny, but the main character's rather dubious views were unknown. Nothing to worry about there.
But the habit grew. One day I found myself watching The Golden Girls with my dear mother and got hooked. Soon she was being forced to tape the programmes every week (it was on way past my bedtime) and it became essential Sunday morning viewing.
From there, things got out of control. I started to binge-watch the Dallas spin-off drama Knots Landing. I can't remember the first time I saw Greg, Paige and the others play out their horrible, narcissistic, money-led lifestyles, but soon I was hooked.
Their lives seemed so far away from my own, I found it compelling, must-see TV.
From memory, Knots Landing appeared on Monday afternoons.
I'd come home from school and it would be the first thing on. We'd sit down and enjoy the slow release of the latest twists and turns. It even became something we bonded over.
But at some point I kicked the habit. An addiction to US soaps was replaced by one far less alarming and damaging - Neighbours.
Don't get me started on Neighbours.
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