With the honourable exception of classics like Casablanca and Brief Encounter, the love story tends to get short shrift from film critics. There’s something very un-English about a movie that seems hell-bent on reducing you to a blubbering jelly. Naked sentiment is slushy and vulgar. Yet if we are perfectly honest, I doubt any of us would have it any other way. Frankly my dear, there wouldn’t be a film industry worth crying about without great big bodice-rippers like Gone with the Wind.

Love stories define our evergreen ache for a romance so magnificent and pure it defies every conceivable adversity, including death. Because the heroes of these larger-than-life fantasies are obviously doomed – an essential ingredient of the classic love story – we feel eternally grateful for our own humble lot. That’s the life-affirming magic of these guilty secrets. They have the nostalgic pull of that Meatloaf album you would rather die than ever admit having listened to in heart-broken ecstasy.

For better or worse, most classic screen romances take their cue from Romeo and Juliet: Shakespeare’s tragedy about star-crossed lovers born on different sides of the street. It’s uncanny how many times Hollywood has re-minted this story, and how it has bounded back into the zeitgeist.

Arthur Hiller’s 1970 melodrama, Love Story, is one of the most dramatic examples, because the genre looked as if it had fallen irretrievably out of fashion a mere five years after David Lean posted his last great romantic pot-boiler, Dr Zhivago (starring Julie Christie and Omar Sharif) in 1965. Old-fashioned romantics were being brushed aside by young rude rebels like Martin Scorsese and Dennis Hopper. The Vietnam War fed a creeping lack of faith in any sort of established order. Drugs and free love diluted the chaste point of shooting an old-fashioned love story.

So Hiller’s deeply square movie about a rich Boston lawyer who falls in love with a bankrupt, terminally ill, student was duly murdered by the critics. No one gambled on Love Story being the box office sensation of the year. The film had little class and less authority. It couldn’t hold a candle to a vintage masterpiece like Alexander Korda’s 1947 version of Anna Karenina. But Hiller’s soap made a quintessentially old-fashioned genre look improbably modern. It has a unique place in the history of the classic love story.

Ryan O’Neal and Ali MacGraw were feted like Clark Gable and Vivien Leigh. They spent the rest of their careers failing to dodge the catch phrase: “Love means never having to say you’re sorry”.

The modern pretenders have come thick and fast. But precious few have the noble credentials of a classic love story. Explicit sex thrillers like Nine ½ Weeks, and broody art house loners like In the Mood for Love, are too wrapped up with infatuation, sleaze, and obsession. Sex in classic love stories is mostly awkward and chaste. Taylor Hackford’s 1982 melodrama, An Officer and A Gentleman, makes a compelling case to be included. Richard Gere delivers a wonderfully tortured performance as a trailer-trash cadet who graduates as an officer and comes back to marry the girl. Fairytale endings are fatal contradiction.

The entire point of the classic love story is that the heroic romance is tragically doomed. They are defined by the cruel pleasure of an unhappy ending, and there is no more spectacular an example in recent times than James Cameron’s 1997 blockbuster, Titanic. The film is as perfectly formed as its scrumptious stars, Leonardo DiCaprio and Kate Winslet. The fiction is rooted in historical fact. The nail-biting action is organically linked to the blind and reckless pride that sunk the ship and cost thousands of lives.

The unprecedented scale of this fabulous classic has yet to be matched. Whatever one thinks of the film’s artistic qualities, there is no arguing with the figures. The classic love story is here to stay. The most distinguished auteurs in the business are being sought to make the next generation of romantic tragedies. The late, lamented Anthony Minghella demonstrated just how hungry the market is with his 1996 Oscar-winning masterpiece, The English Patient. The film, miraculously assembled from Michael Ondaatje’s complex book, stars Ralph Fiennes as a disfigured explorer who is forced to abandon his wife in a cave. It is an eloquent reminder of how reliant the love story is on great literature.

Taboos are also being eroded. Ang Lee’s controversial film, Brokeback Mountain – the first classic gay love story to be embraced by a mainstream audience – demonstrates how refreshingly far the genre has come without losing its Romeo and Juliet charm. Far from leaking respect as an emotionally simplistic genre, the classic love story is irrefutable proof that love really does conquer all.