There are at least five love stories contained within this one, stylish masterpiece - George Cukor's lustrous template for every witty rom-com that followed. Katharine Hepburn's monstrous Tracy Lord is an heiress principally in love with herself and her own burnished rectitude. And although it is Cary Grant who finally gets his girl, it is James Stewart's bemused reporter who gets the most romantic scene: a moonlit kiss by a swimming pool which knocks Tracy sideways - and off her pedestal once and for all. The only film, incidentally, to feature a chat-up line from yachting: "My, she was yah."
Humphrey Bogart and Ingrid Bergman in Casablanca (1942)
Bogie had more than his fair share of great screen romances - think of the burning intensity of his scenes with future wife Lauren Bacall in To Have and Have Not (1944), or his odd-couple badinage with Katharine Hepburn in The African Queen (1951) - but none of them amounts to a hill of beans in comparison with his cruelly curtailed love affair with Ingrid Bergman in Casablanca.
Trevor Howard and Celia Johnson in Brief Encounter (1945)
With its repressed Englishness and stirring Rachmaninoff soundtrack, Brief Encounter - directed by David Lean and written by Noël Coward - is everyone's idea of a perfect weepie. Housewife Celia Johnson and doctor Trevor Howard meet at a railway station every Thursday and a close friendship gradually becomes something more. Not wanting to distress their families they decide to part. Johnson almost takes the Anna Karenina track, but something stops her. Perhaps she knows that her husband, to whom she is silently confessing her story, is truly her real - if rather humdrum - love. Rather than a hymn to adultery, Brief Encounter can be seen as a subtle defence of married life.
David Niven and Kim Hunter in A Matter of Life and Death (1946)
That loveable rogue, David Niven, proves that he can woo a girl in the most unlikely of circumstances in Powell and Pressburger's fantasy masterpiece. Hurtling towards the ground and certain death in his wrecked WWII bomber, Peter Carter (Niven) starts talking to an American wireless operator called June (Kim Hunter), and it is love for her which makes him determined to live.
Katharine Hepburn and Spencer Tracey in Adam's Rib (1949)
If the sign of true love is a good fight between equals, as most screwball comedies would have us believe, then Adam's Rib is its platonic exemplar. Designed as a vehicle for Katharine Hepburn and Spencer Tracy, who had by that time made five films together and were long-term lovers (but married to other people), the original screenplay was written by a couple. Ruth Gordon (who later starred in Harold and Maude) came up with the idea alongside her husband Garson Kanin, screenwriter and author of one of the most glorious Hollywood memoirs ever written.
The plot: married lawyers take the respective sides of a husband and wife in an attempted murder case. All hell breaks loose at home and in court, until feminism conquers all. The moral? If Adam's spare rib had been fashioned into Katharine Hepburn, there would have been no need for a battle of the sexes in the first place. She would have won there and then.
Lady and the Tramp (1955)
There's a love story at the heart of every great Disney film, but Lady and the Tramp has a special kind of romance. The Tramp may be an adorable scruff, but he knows how to treat Lady: moonlight, the best restaurant service and the last meatball. However, there's more to their tryst than a spaghetti kiss, as the Tramp shows Lady another kind of life, and she lends him acceptance in a happily-ever-after ending.
Jack Lemmon and Shirley MacLaine in The Apartment (1960)
Jack Lemmon is superb as the dim insurance company clerk CC "Buddy Boy" Baxter lending his Manhattan flat to his bosses to conduct their affairs in Billy Wilder's 1960 film The Apartment. Lemmon's character is in love with elevator attendant Fran Kubelik (Shirley MacLaine) and their chemistry is superb. The film won five Oscars, including Best Screenplay, and ends with the memorable lines: "Did you hear what I said, Miss Kubelik? I absolutely adore you." "Shut up and deal."
Richard Burton and Elizabeth Taylor in Cleopatra (1963)
Joseph L Mankiewicz's $44 million movie may have been a piece of sheer cinematic folly, but it also captured on celluloid one of the defining moments in modern celebrity culture: when Liz met Dick. Taylor hadn't been impressed with the flirtatious Burton until they filmed their first scene together. "There was no dialogue," she remembered later, "we had to just look at each other. And that was it - I was another notch."
Warren Beatty and Faye Dunaway in Bonnie and Clyde (1967)
Bonnie and Clyde was a new kind of screen rebellion, and a seductive one at that. On one hand, cinema had seen few more physically alluring pairings than Faye Dunaway and Warren Beatty. On the other, stand back a little and you remember that you're on the run with two increasingly desperate killers in a world filled with anger, helplessness and suspicion. Still, the couple stick it out to the bitter end, finally dying in in a suitably orgasmic hail of bullets.
Bud Cort and Ruth Gordon in Harold and Maude (1971)
This most unlikely and transgressive of pairings - between deranged, death-obsessed 19-year-old Harold (Bud Cort) and joyfully anarchistic 79-year-old Maude (Ruth Gordon) - was dismissed by critics at the time (the film was "anti-heterosexual propaganda," according to New York magazine), but its strange atmosphere of romantic hopefulness has ensured a long cult afterlife.
Woody Allen and Diane Keaton in Annie Hall (1977)
Woody Allen's semi-autobiographical 1977 movie is more about the ending of a love affair than its heady beginning. He wrote the part of Annie Hall with his then-girlfriend, Diane Keaton, in mind; her relationship with his character, Alvy Singer, may ultimately be a "dead shark", but before the rot sets in, Allen creates an unforgettable portrait of love, lurve, loave and luff.
Richard Gere and Debra Winger in An Officer and a Gentleman (1982)
The eternal battle between ambition and love finds its most complete Eighties exposition in this stirring tale of a naval cadet with attitude and a perfect white uniform, and the girl from the wrong side of the tracks for whom he falls. Taylor Hackford turns a hackneyed story into a stirring sob-fest and that final scene, where Gere marches into the factory and sweeps Debra Winger up in his arms, will always make impressionable teenage girls swoon.
Molly Ringwald, Andrew McCarthy and Jon Cryer in Pretty in Pink (1986)
Few survive their teenage years without becoming a corner of a love triangle, and director John Hughes creates the best ones on film. Andie (Molly Ringwald) and Blane's (Andrew McCarthy) romance manages to blossom although they come from different sides of the tracks, but mostly the viewer wants Andie's best friend Duckie (Jon Cryer) to get the girl. It's difficult to watch her reject him - especially after the best Otis Redding impersonation in cinema.
John Cusack and Ione Skye in Say Anything... (1989)
There was a brief period, in the late Eighties, when underachieving, unlucky-in-love young men everywhere were given hope by two words: Lloyd Dobler.
As played by Cusack, the hero of Cameron Crowe's first and sweetest film wears a shabby trench coat, has no career prospects beyond "kick-boxing", and no plans for the future except getting the high school golden girl, Diane Court (Ione Skye), to fall in love with him. This is exactly what he does, using only the power of pure optimism and a boombox. Their courtship is awkward, funny and all too believable, without a hint of irony or cynicism. And when the inevitable break-up comes, we get one of teen cinema's most bittersweet lines: "I gave her my heart, and she gave me a pen."
Patricia Arquette and Christian Slater in True Romance (1993)
"You're so cool, you're so cool, you're so cool!" coos Patricia Arquette's Alabama to her husband Clarence (Christian Slater) in this pulpy romantic thriller, directed by the late Tony Scott and written by Quentin Tarantino.
Clarence is an Elvis-worshipping comic book store clerk with a penchant for Hawaiian print shirts and Sonny Chiba movies; Alabama's a leopard-print-clad call-girl with peroxide blonde hair. Theirs is a love so pure, so intoxicating, that you can't help but root for them as they go on the run with a suitcase full of mob contraband.
Tom Hanks and Meg Ryan in Sleepless in Seattle (1993)
When Tom Hanks's lonely widower winds up on a late-night radio talk show reminiscing about the wife he lost, Meg Ryan's unhappily engaged writer listens in from the other side of America and falls in love. It may be about as far-fetched a meet-cute as can be, but in the final reckoning the combined charms of Hanks, Ryan and screenwriter Nora Ephron are irresistible.
Kenneth Branagh and Emma Thompson in Much Ado About Nothing (1993)
Kenneth Branagh turned Shakespeare's high comedy into a ripe love-letter to Tuscany. While some of the American accents grate (Keanu Reeves), the playful banter between Branagh's Benedick and Emma Thompson's Beatrice is charming. "I do love nothing in the world so well as you," says Benedick. Sadly, Branagh and Thompson's real-life romance was about to hit the rocks.
Ralph Fiennes and Kristin Scott Thomas in The English Patient (1996)
So in love was Ralph Fiennes's English patient (really a Hungarian count) with Kristin Scott Thomas's adulterous Katharine Clifton that he handed over control of North Africa to the Nazis so that he could rescue her from a cave in the Sahara - even though he knew she was already dead.
George Clooney and Jennifer Lopez in Out of Sight (1998)
Stephen Soderbergh's effortlessly addictive crime caper is built in the image of its leading man, George Clooney - it's slick, charming and almost impossibly easy to watch. The love affair at its heart is between Clooney's suave bank robber and jailbird and Jennifer Lopez's no-nonsense US marshal. Despite the unlikeliness of their first encounter - the pair are locked together in a car boot as Clooney flees a Florida prison - their relationship is utterly convincing.
The sex appeal of the film's stars, Soderbergh's sure-footed direction and David Holmes's slinky soundtrack all add to the chemistry.
Maggie Cheung and Tony Leung in In the Mood for Love (2000)
In Sixties Hong Kong, Maggie Cheung and Tony Leung live in the same tenement building, and pass each other on the stairs on their way to get noodles. Through a series of accidents they realise that their respective husband and wife are having an affair.
Mutual pain draws them together - as does a shared passion for martial arts comics. But they are unwilling to stoop to the level of their unfaithful spouses and so the friendship remains platonic. Director Wong Kar-wai's lush visuals and intoxicating score make this film a beautiful sensory experience - but Cheung and Leung's affecting performances give it its heart.
Jim Carrey and Kate Winslet in Eternal Sunshine of the Spotless Mind (2004)
Michel Gondry's film, which takes its title from a poem by Alexander Pope, asks a fundamental question: is love a matter of character or circumstance? In other words, if you had no memory of someone and met them anew, would you fall for them inevitably, regardless of time or place? Or could you resist them in another life?
Jim Carrey and Kate Winslet play a couple who willingly have their memories erased after they split up. Later they meet again, and begin again, and when they discover that they have been here before - that there's no reason why it shouldn't end just as badly a second time around - they go ahead anyway. Love, the film seems to say, is a leap of faith, despite and because of all evidence.
Jake Gyllenhaal and Heath Ledger in Brokeback Mountain (2005)
Are the greatest screen romances those which end badly? Ang Lee's epic adaptation of Annie Proulx's short story about a love that dare not speak its name - indeed, a love that barely speaks at all - was rich, tender and tragic.
Ranch-hand Heath Ledger and rodeo cowboy Jake Gyllenhaal meet and fall in love; each marries a woman (Michelle Williams and Anne Hathaway respectively), but they just can't quit one another.
Ellie and Carl in Up (2009)
Hats off to Up's creators for achieving in a 10-minute montage what The Notebook failed to accomplish in two hours: an honest and touching look at one couple's life together.
Watching adventurous Ellie and hesitant Carl move together from gap-toothed childhood through quietly blissful marriage to cosy old age (their dreams of relocating to South America derailed by life) is enough to restore anyone's faith in love.
Jesse and Céline (Ethan Hawke and Julie Delpy) in Before Sunrise (1995), Before Sunset (2004) and Before Midnight (2013)
In 1994 Richard Linklater made an unfashionably talky movie called Before Sunrise, about an American backpacker (Ethan Hawke) and a Sorbonne student (Julie Delpy) who meet on a train and tramp happily round Vienna for a day and night.
They arrange to meet in six months, but we never find out what happens. Then Linklater resurrected their story a decade later in 2004's Before Sunset. This time round - shot in Paris, in real time - the couple have even less time to get reacquainted, just 90 minutes before Hawke must return to his two children and ailing marriage in the States. The set-up is so romantic, the script so spot-on, you're left light-headed for days after seeing it. And 2013's Before Midnight, we saw the pair finally together, raguing and eventually reconciling.
