Last week, one of the national film critics emailed to ask whether I had a copy of The Apartment he could borrow. “The problem is, it’s being re-released and I’ve got to review it and I really don’t fancy a trip to the BFI,” he said.

I was shocked. I can understand why he wouldn’t want to drag himself to a screening theatre to watch the latest Madonna film, but The Apartment? For my money, it’s one of the two or three best films ever made. He had seen if before, of course, and was conscientious enough to want to re-watch it on DVD. But even so. If I had the opportunity to go and watch The Apartment on the big screen for free, I think I would go.

Made in 1960, it was the highpoint of Billy Wilder’s extraordinary career as a writer-director, starting with The Major and the Minor (1942) and encompassing The Lost Weekend (1945), Sunset Boulevard (1950), Sabrina (1954), Witness For the Prosecution (1957) and Some Like It Hot (1959), among others. The Apartment was a comedy, but unlike Wilder’s previous comic films it was shot through with Wilder’s tragic sensibility. Even Stalag 17, his groundbreaking comedy about life inside a Nazi prisoner-of-war camp, was light by comparison.

It is a fair bet that most of Hollywood’s writer-directors, particularly those at the top of their game, would have balked at having the female lead attempt to commit suicide. Not Wilder. He was a confident enough artist to take that risk, knowing it could have killed The Apartment stone dead at the box office. In fact, the inclusion of the suicide scene, in which Jack Lemmon discovers an overdosed Shirley MacLaine, is what lifts The Apartment from being just another (admittedly very good) romcom into the realm of an all-time classic.

Like Chekhov, who described his own plays as “comedies”, Wilder knew that the key to creating a great work of dramatic art was to straddle the line between comedy and tragedy, staying just the right side of it most of the time, but not being afraid to occasionally stray on to the wrong side. Tragi-comedy is the toughest genre of all to pull off -- and Wilder himself came a cropper when he tried it again in Kiss Me, Stupid. But when you can make it work, as he did in The Apartment, the result is far more satisfying than a drama that falls more squarely on one side of the line or the other.

At the 1961 Academy Awards, The Apartment won five Oscars, including Best Picture, Best Director and Best Original Screenplay. As Moss Hart handed Wilder his screenwriting statuette, he leaned over and whispered, “This is the moment to stop, Billy.” “And how right he was,” Wilder told his biographer, Maurice Zolotow, fifteen years later. It simply doesn’t get better that The Apartment.