In 1994, the doctors and nurses crashed through the doors of County General to save patient after bloody patient – and save the world from all the tedious TV that came before!

ER is 25 years old. And this means you should all drop whatever you’re doing now and dedicate the next 331 hours of your life to reminding yourself what an incredible series it was.

And it was. The overwhelming majority of shows from the past 25 years would be dramatically different if it wasn’t for ER. The murmured dialogue of The Sopranos and The Wire. The dramatic surge of Breaking Bad. The sheer spectacle of Game of Thrones. The breathless professional jargon of Line of Duty. All of them, in one way or another, owe a debt of thanks to ER.

Of course, this might not be entirely evident when you first watch it. Stumble across the wrong episode and you might be bewildered by its sentimentality, or the ridiculous matinee-idol looks of its cast. But this is to be expected. Like other shows that were groundbreaking at the time, the wider culture has subsequently absorbed what made ER so great and spread it wide across everything it could. There are elements of ER in almost every TV programme you’ve watched in the last 20 years.

If you really want to experience the about-turn that ER represented, perhaps it’s best to spend the next 15 years of your life watching TV shows that were made before 1994. Take something like St Elsewhere, which ran for six years in the mid-1980s and was almost entirely made up of long, unbroken scenes where doctors wandered around aimlessly having long meandering conversations. For years, almost since the invention of the form, this is what television looked like.

Facebook Twitter Pinterest In its glory days it was unstoppable … ER. Photograph: Allstar/Cinetext/Warner Bros

Then came ER. The first episode arrived like a hammer attack. A building collapses within the first four minutes, sending the cast into a frenzy of quick-fire medical jargon as a jittery percussive score kicks in. Stretchers flood into the hospital. We see the walls and ceiling of the hospital from the viewpoint of a wheeled-in patient. Teams of doctors attend to multiple people, communicating in long streams of deep-cut hospital terminology, punctuated by short reassurances. It’s a whirling, breathless sequence that leaves both the camera and the audience racing to keep up. When it finally comes to an end, shaking with tears after seven or eight minutes, everything else on television felt it came from another planet.

Facebook Twitter Pinterest Nobody was bigger than the show … Julianna Margulies and George Clooney in ER. Photograph: Allstar Picture Library/Alamy

Better yet, despite its influence, ER holds up incredibly well today. Although it would eventually succumb to a comfortable soapiness, the propulsive set-pieces are still remarkably sophisticated. They’re not just technically impressive but, in their refusal to lead viewers by the hand, they laid the seeds for almost every show you love today. You couldn’t just watch ER the old way, letting it flop across your eyes like wallpaper. You had to actively be a participant to get the most out of it.

Obviously it helped that it was pretty to look at. This was, after all, the show that launched George Clooney into the stratosphere. His character’s charm, his heroism, his quiet heartbreak, his attraction to Carol Hathaway; it lined him up perfectly for a career as an A-lister. But while he attracted the lion’s share of the attention, the cast was rammed with talent of his calibre. Anthony Edwards, Noah Wyle, Julianna Margulies, Eriq La Salle, Maria Bello, Alex Kingston, Parminder Nagra, Linda Cardellini and Angela Bassett all had stints on the series, and each had several chances to shine.

But none were bigger than the show itself. ER was basically copied into irrelevance within a decade, but in its glory days it was unstoppable. It was a show that lured Quentin Tarantino, fresh from the glow of winning an Oscar for Pulp Fiction, to direct an episode. It was the show that hired Ewan McGregor, then arguably the biggest movie star in the world, to appear in one episode. And this was in the 1990s. The line separating film and TV at that point was vast. Talent of Tarantino and McGregor’s ilk would only cross it for something truly important. ER was that something.

• ER is available in full on All4 now.