Word Watch

"It turns out there's no sell-by date on Christmas spirit," said the Radio Times's Tim Glanfield, "and a film that encapsulates it will stay with us for generations."

It's A Wonderful Life won the same poll when it was last held in 2013. Several modern films came close to winning this time around, including Elf, The Muppet Christmas Carol, Love Actually and Home Alone - but none could knock the old classic from the top spot.

But what is the film about, and why does it have such enduring appeal?

It tells the story of George Bailey, a generous but small-time businessman who's big ambitions have been thwarted: both by his instinct to put others first and a particularly ruthless rival.

When calamity strikes one Christmas Eve, he cracks. Stumbling onto a bridge, he is determined to throw himself off and commit suicide. However, prayers from his family reach heaven, and a guardian angel (named Clarence) descends to rescue him.

Then angel shows him what the world would have been like if he had never been born. Slowly George learns a profound lesson: he may not have wealth, but his time on Earth has transformed the lives of those around him for the better.

"Strange, isn't it?" Clarence tells George: "Each man's life touches so many other lives. When he isn't around he leaves an awful hole, doesn't he?"

This idea has moved audiences for decades. "It verges on the sentimentalEmotional and unscientific. but never too much," claims film critic Barry Norman. "Far more it's simply heart-warming - the grandaddy of all feel-good movies."

And while it does deliver a happy ending, its depiction of a man struggling with the pressures of daily life hits home too. This year, lines from the film's script have been painted onto train platforms across the UK - raising awareness of mental illness, and highlighting how difficult the festive period can be for some people.

What makes the perfect Christmas movie?

Q & A

It is about nostalgiaThe feelings of happiness and slight sadness you get when remembering the past. and tradition, some argue. Just like a Christmas turkey dinner, classic movies are a comforting ritual that we rely on to bring us joy. The simple and uplifting wisdom of It's A Wonderful Life is a welcome relief from a confusing and chaotic modern world.

Not necessarily, others respond. Rather than letting us escape from the world, the best Christmas films try to stay relevant to contemporary issues. It's A Wonderful Life is a heart-warming Christmas tale, but it also depicts the toll that the daily grind can take on mental health - something many people still identify with.

Bombed: The film ended up making a loss of $525,000. However, it had a respectable showing at the Oscars, picking up five nominations for Best Picture, Best Director, Best Actor, Best Film Editing and Best Sound Recording.

Radio Times: According to a survey of more than 7,000 people conducted by RadioTimes.com.

Rival: Henry F. Potter. In the film, he wants to destroy George's business and take over the whole town.

Angel: The film is based on a short story by Philip Van Doren Stern. He, in turn, got the inspiration for the guardian angel character from Charles Dickens's A Christmas Carol.

Platforms: "At Christmas time, in particular, we wanted to ensure people know that help is available if they need it," said organiser Colin Leslie.

What do we know?: Despite its feel-good credentials, the film was subject to conspiracy theories when it was first made - some accusing it of spreading communist ideas. Indeed, a report written by the FBIThe Federal Bureau of Investigation, which investigates crimes on a national level in the USA. found that George Bailey's story contained subversive tendencies, including "demonising bankers" and "attempting to instigate class warfare".

What do we not know? How tastes will change in the future. For example, the 2013 edition of the same survey ranked Richard Curtis's 2003 Love Actually in second place - it has subsequently fallen to fourth. Furthermore, there is much disagreement about what constitutes a Christmas film. The classic debate centres around the film Die Hard. Some are convinced it is a Christmas movie; others, not so much.