Image copyright Rex / Shutterstock

It's been 20 years since Buffy The Vampire Slayer first hit our TV screens. It has fans all over the world, and made a star of its lead actress Sarah Michelle Gellar.

A TV series based on a not-great movie about a Californian teenager who attends high school by day and fights vampires by night, seems an unlikely candidate to be a serious contender to become a TV classic and hugely influential piece of popular culture.

But Buffy managed it and after close to 150 episodes - with its final outing airing in 2003 - its influence is still felt today as a truly ground breaking piece of work.

Here are some of the things that Buffy has given the world of entertainment.

Image copyright Sky One/PA Image caption Sarah Michelle Gellar became a household name after starring in the cult show

Strong, complex women on screen.

In TV and film it's all too common for female characters to be the love interest or the support to a male lead.

Buffy successfully put a woman at the centre of the series, and led the way for characters like The Hunger Games' Katniss Everdeen, The Force Awakens' Rey, Homeland's Carrie Mathison, and so many more.

Whip-smart dialogue filled with great pop culture references.

This was a trademark feature of Buffy - one example, after a gruesome multiple murder at a college fraternity house, a demon approvingly comments: "It's like somebody slaughtered an Abercrombie and Fitch catalogue."

Series ranging from Gilmore Girls to Family Guy gleefully use dialogue in a similar, although less gruesome, way.

Image copyright Getty Images Image caption Joss Whedon (far right) with the cast of The Avengers in 2010

Joss Whedon!

Buffy's show runner is now one of the biggest names in Hollywood.

Two of the films in the Top 10 highest grossing of all time were directed by him - Marvel's The Avengers and its sequel Avengers: Age of Ultron. Both took over $1.5bn (£1.23bn) and he also had a role overseeing other successful Marvel films.

And it all started with the experience he got writing and directing Buffy.

Standalone storylines with an ongoing narrative leading up to an end of series 'Big Bad'.

When writer/producer Russell T Davies re-launched Doctor Who in 2005, he changed its format to one that was similar in many ways to Buffy.

The episodes in each series lead up to a climax where the main threat has been bubbling under the surface for several episodes.

Image copyright Getty Images Image caption Once More, With Feeling saw the Buffy cast spontaneously burst into song

La La Land?

Without Buffy's brilliant musical episode Once More, With Feeling would Ryan Gosling and Emma Stone's movie ever have been green-lit?

Actually, yes, it would have been. But if you enjoyed the singing dancing love letter to LA which didn't win best film at this year's Oscars, you could do worse than to check out Buffy's musical extravaganza.

It's exactly like La La Land, but with added demons.

It also set a trend for other TV shows to unexpectedly feature a musical episode halfway through a series, including medical comedy Scrubs and medical drama Grey's Anatomy - and an upcoming Supergirl/The Flash crossover.

Thanks Buffy, you saved the world - a lot.

Media playback is unsupported on your device Media caption What have the Scooby Gang done since Buffy?

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