Warning: This story contains spoilers!

Image copyright ITV Image caption There are several characters with a motive to harm Ken

Coronation Street fans were left with a classic soap cliffhanger on Monday after Ken Barlow (William Roache) was found at the bottom of his stairs unconscious.

And fans were left wondering if he fell or if he was pushed.

The long-running Street resident suffered a stroke in the autumn, so many wondered if he was ill again.

But with Barlow having rubbed up family members, neighbours and acquaintances the wrong way in recent weeks, could he have been shoved?

We take a look back at some of the best TV whodunnits from over the past few years.

Image copyright AP Image caption The original Dallas ran from 1978 to 1991

Who shot JR?

Who could forget this long-running saga involving the Dallas oil baron we all loved to hate?

It took eight months for viewers to discover that it was JR's sister-in-law and former mistress, Kristin Shepard. But not before JR's long-suffering wife Sue Ellen got the blame first and was jailed.

T-shirts printed with the slogans "Who Shot JR?" and "I Shot JR" flew off the shelves in the summer of 1980.

The storyline became one of television's first big water-cooler moments and prompted pretty much every soap going to get in on the cliffhanger act.

Image caption Everyone was guessing who shot Phil in Albert Square

Who shot Phil Mitchell?

So it didn't have the glamorous Dallas backdrop but the British answer to the JR mystery was, of course, who shot Phil Mitchell?

The EastEnders bad boy came under fire in 2001 but fans only had to wait a month to find out who it was, although many suspects had come under the spotlight during that time, including Mark Fowler, Ian Beale, Steve Owen and Dan Sullivan.

But in April 2001, it transpired that Phil's ex, Lisa, had pulled the trigger. She confessed to Phil himself - while also admitting that she still loved him.

EastEnders followed up its successful storyline with several other whodunnits, including "Who killed Lucy Beale?" and "Who killed Archie Mitchell?".

Image caption The identity of the father of Michelle Fowler's baby kept EastEnders' viewers gripped

Who's the daddy?

Another twist on the whodunnit, this device was first used by EastEnders back in 1985.

This time, the mystery surrounded teenager Michelle Fowler who had become pregnant. But who was the father? There were several suspects, including Tony Carpenter and Ali Osman but of course, we all now know that it was Dirty Den, her best friend's dad.

Image caption 'Scandi noir' has grown in popularity in the UK

Who killed Nanna Birk Larsen?

Of course, it's not just soaps and their fans who love a good old whodunnit. Many crime dramas have centred entire series on finding an elusive killer.

Scandinavian drama The Killing (2007) saw Sophie Grabol's detective Sarah Lund investigating the rape and murder of teenager Nanna Birk Larsen, whose body was found in the boot of a car submerged in a lake.

Under suspicion on this occasion were Copenhagen mayoral candidate Troels Hartmann, along with his campaign manager Morten Weber, while Larson's teacher Rama also found himself on Lund's radar.

In the end, it turned out to be family friend Vagn Saerbaek - and it wasn't the first time he had killed either, having also murdered Lund's partner and a former girlfriend, too.

Image copyright Twin Peaks Productions Image caption Laura Palmer's death gripped the town of Twin Peaks

Who killed Laura Palmer?

David Lynch's cult 1990s hit series, Twin Peaks, was entirely based on this question.

Was it Laura's psychiatrist Dr Lawrence Jacoby who was infatuated with the teen? Her boyfriend Bobby? What about Benjamin Horne, who had hired Laura as a prostitute? Drug dealers Leo Johnson and Jaques Renault also came under the spotlight.

But it was Laura's father who murdered her, while possessed by the demon Killer Bob.

Now fans are excited about series three arriving in May, 27 years after the first season aired. Watch this space.

Image copyright ITV Image caption The third and final series of Broadchurch has focused on a rape storyline

Who killed Danny Latimer?

The first series of Broadchurch in 2013 was a huge hit for ITV, as crime-fighting duo DI Hardy and DS Miller tried to solve the mystery of who murdered a local schoolboy.

Viewers were addicted to the twists and turns of the plotline as Danny's dad and the local vicar were among those under investigation. The moment when DS Miller (Olivia Colman) discovered her husband was the murderer was one of television's scenes of the year.

Series two couldn't quite match the original's dizzy heights but the current third and final series is gripping viewers once again as Hardy (David Tennant) and Miller try to catch a serial rapist.

Follow us on Facebook, on Twitter @BBCNewsEnts, or on Instagram at bbcnewsents. If you have a story suggestion email entertainment.news@bbc.co.uk.