A wide streak of romantic sentimentality means history has judged Titanic poorly, but if you were around to experience it, there hadn't been a cinema phenomenon like it for at least a decade.

There also seems to have been a conspiracy surrounding its success, as if everyone – even the Academy Awards – plugged it remorselessly. Few other movies are the biggest commercial hit in a given year and scoop the pools of the major awards as well; Titanic not only did both, it smashed the records in both areas (and more, not the least was its $200m cost), winning 11 Oscars and blitzing the box office.

And like all big ideas, an essentially simple one; tell an ill-fated Romeo and Juliet story with the backdrop of the world's most famous peacetime maritime disaster, but don't concentrate too much (nor too little) on either and polarise your audience. The Wachowski brothers tried the same thing in The Matrix Reloaded, but the result was an uncomfortable lurching from philosophy to action and back again.

Whether you were there for the love story or the CG effects and sets, at least Cameron enmeshed the two story strands into one narrative effectively, cementing his talent as one of modern cinema's most talented writer/directors to the wider mainstream instead of just teenage boys of the world.

Drifter and adventurer Jack (DiCaprio) and repressed, buttoned down good girl Rose (Winslett) couldn't be more different. Jack represents the easygoing freedom of the lower classes, Rose – betrothed to cad Hockley (Zane) – lives in the gilded cage of expectations and appearances in the monied class.

As the world's newest, biggest ship steams across the Atlantic Ocean towards the US east coast, the two fall in love, and we're privy to their emotional entanglements as they try to make their worlds merge as their hearts have done. As Cameron himself said (an apparent authority on the subject, after about five marriages and a habit of hooking up with his leading lady – in this case, Rose's modern day granddaughter Suzy Amis), it's a kind of love we all dream about but rarely find.

In an instant, as we join two men in a crows nest on watch – the romance is all but shelved and we're left to enjoy the spectacle of the most famous sinking in history in glorious and horrifying detail, made human as told through Jack and Rose's eyes. They see the dark iceberg looming in the dark, and the drama rises to fever pitch and stays there virtually for the full last hour as the ship goes down.

The reasons people hated it are as credible as the reasons people loved it. The love story and the personalities that orbit it are bland and predictable; the villains do everything to broadcast their intentions except twirl cartoon moustaches while those we're supposed to sympathise with are put in the best possible light.

Andrews (Garber) laughs at Rose's joke about Sigmund Freud and the male preoccupation with size when Ismay (Hyde) is describing why he chose the name Titanic, while Ismay himself displays his stupidity by not knowing who Freud is – it's plain who we're supposed to like and who we're supposed to hold in contempt. The fact that good actors like David Warner and Kathy Bates fit into the same corny moulds is a shame, but even in the almost four hour running time, Cameron had little time for complexity of character.

Technically, it displays brilliance and attention to detail that we rarely see in movies anymore but consistently see when James Cameron's behind the megaphone. His reputation as a control freak over every single department is legendary, but apparently for the best. The life-sized Titanic half-replica built at Fox's Rosarito ocean set had a giant gimbal to simulate the ship dipping down in to the water, the most impressive set effect ever seen in a film at the time.

Together with the attention given to every costume and ship fitting and fixture (particularly as it was all built based on a real ship), the design and look of the film are faultless. It's also tightly edited so the 3.75 hour running time doesn't seem much longer than a normal feature film.

It made a major star out of DiCaprio, and although it was a reputation he deserved as an actor after his performances in films like The Basketball Diaries and What's Eating Gilbert Grape, the role of Jack Dawson calls for little talent.

And after drifting in the background of Merchant Ivory-style Bronte adaptations, it propelled Winslet to instant recognition, a level she's used to make her way into off-centre films rather than cash in on her leading lady cachet. The cast is peppered with big names, but none of them overshadow the casting of anyone else, or the real star of the show – the effects during the sinking sequence.

One of the most influential films of the 1990's, although the character and plot melodramatics seem cheesier upon repeat viewings.