Jim Stark (Rebel Without A Cause)
Impact: Brando beat James Dean out of the gates in the teen rebel stakes, but The Wild One proved too uncouth to make an impact beyond the initial scandal.
Dean, in Stark contrast, sweetened the outrage to define the American teen as misunderstood and melancholy - an air of vulnerability that Dean's own death only enhanced.
Influence: The default setting for screen teens ever since. Paul Newman and Steve McQueen took on the mantle left by Dean, while Robert Pattinson's bequiffed vampire Edward Cullen is the latest to borrow Jim Stark's proto-emo angst.
If He'd Never Existed: We'd be nicer to our parents.
Lulu (Pandora's Box)
Impact: Louise Brooks' bobbed harpie scandalised conservative audiences but thrilled '20s swingers with her screw-the-rules 'tude and tragic vulnerability.
Influence: The famous look alone initiated a fashion trend, but Lulu opened the doors to risque performers like Marlene Dietrich and Mae West, until the creation of the censorious Hays Code slammed them shut.
Yet feminine sexuality had become part of Hollywood, and the Lulu look remains iconic shorthand for "a good time" - check out Melanie Griffith in Something Wild for proof of that.
If She'd Never Existed: Cinema wouldn't have got past first base.
Inspector Clouseau (The Pink Panther)
Impact: Clouseau was, of course, only supposed to be a supporting role in The Pink Panther , but Peter Sellers' indelible presence meant that he stole the show.
And why not? Clouseau was the pompous, accident-prone gendarme audiences had been waiting for their entire lives.
Influence: Clouseau is so memorable he cannot even be contained by Sellers' death, although none of the alternative versions, spin-offs or remakes can muster anything like the laugh ratio of Clouseau v.1 in full flow.
Seller's immersive performance, creating the silliest of effects through merciless attention to detail, has inspired countless comedians, most recently Sacha Baron-Cohen's Borat and Bruno.
If He'd Never Existed: Nobody would snigger when they get arrested in France.
Indiana Jones (Raiders Of The Lost Ark)
The Impact: Road-tested by Han Solo, Harrison Ford's rogueish appeal found perfect expression in Indy, the professor whose day job came second to globe-trotting adventure.
It was old-school fantasy, sure, but Indy's battered charm and laconic wit kept pace with the cynical, larger-than-life 1980s.
Influence: It sealed Ford's box office rep - and Spielberg's, too - and rip-roaring nostalgic adventure with bells and whistles became a summer movie must-have.
The Mummy , National Treasure , The Da Vinci Code - every one seems to have a strangely familiar athletic professor at their helm.
If He'd Never Existed: We'd no next to nothing about holy relics.
Virgil Tibbs (In The Heat Of The Night)
Impact: Sidney Poitier was already cinema's poster-boy for the civil rights movement after The Defiant Ones and his Oscar for Lillies of the Field .
But as the city cop demanding to be called "Mr Tibbs" by Rod Steiger's bigot sheriff at a time when tensions were never higher (the film was released between the assassinations of Malcolm X and Martin Luther King) , Poitier galvanised black American and made the whites feel ashamed.
Influence: Two sequels for Poitier's Tibbs, but more than that he sowed the seeds for a much more in-your-face approach to black presence on-screen.
Shaft , Superfly and blaxploitation were around the corner, and even Eddie Murphy's debut in 48 Hrs owes something to Tibbs.
If He'd Never Existed: Black characters would still be second class citizens on-screen.
Tom Powers (Public Enemy)
Impact: Edward G. Robinson's Little Caesar got there first, but James Cagney's titular Public Enemy became the touchstone for the classic Hollywood gangster.
Powers' physical violence was matched by Cagney's speeded-up and spat-out line readings, winning the battle of naturalism versus mannerism in the early talkies.
Influence: Close your eyes and picture a Prohibition-era street punk; chances are it's Cagney who holds sway - the model for Bugsy Malone , Once Upon a Time in America , and Public Enemies (especially Stephen Graham's Baby Face Nelson).
But Cagney's influence extends beyond the genre, with Malcolm McDowell being one of the obvious beneficiaries of Powers' impudent insanity.
If He'd Never Existed: Cinema would be as slow and stately as theatre.
Impact: Along with fellow Aussie Russell Crowe's Maximus Decimus Meridius, Hugh Jackman's admantium-clawed mutant ushered in a new breed of man's man to kick 90s irony into touch.
The film's impressive box office take, against a relatively small budget for a blockbuster, proved that taking things seriously would work.
Influence: Comic book heroes, so often prone to camp on screen, showed their true, multi-faceted, colours with psychological frailties and convincing characterisation.
Jackman himself made a star, but more importantly proved that unexpected casting would work. Next stop: Christian Bale as Batman and RDJ as Iron Man.
If He'd Never Existed: Half the blockbusters currently in production would be gone, replaced with spin-offs of old TV shows.
Frank Bullitt (Bullitt)
Impact: With his rebel cool, anti-authoritarian snarl and refusal to heed the speed limits, Steve McQueen should never have been allowed anywhere near a police station unless it was behind bars.
But it's precisely that contrast that makes Bullitt, the turtleneck-wearing, Mustang driving maverick, such a new kind of cop.
Influence: Within years, every screen cop was an (anti)-heroic rogue who did things his way, from Popeye Doyle to 'Dirty' Harry Callaghan to Serpico. The cliche of
the supercop is still so strong that The Other Guys would be impossible without it.
If He'd Never Existed: Screen cops would still be doing things by the book.
Phyllis Dietrichson (Double Indemnity)
Impact: Dietrichson wasn't the first femme fatale ( The Maltese Falcon 's duplicitous Brigid O'Shaughnessy predates her, for starters).
Yet Barbara Stanwyck's murderously bored housewife, written up by Billy Wilder and Raymond Chandler, made film noir's connection between sex and violence explicit, using little more than a dressing gown and a saucy anklet.
Influence: Both immediate - Dietrichson became the template for most 40s femme fatales - and long-lasting, her shiftiness echoed in future generations of fiery dames from Kathleen Turner in Body Heat to Linda Fiorentino in The Last Seduction .
If She'd Never Existed: Love stories would always have happy endings.
Ethan Edwards (The Searchers)
Impact: That John Wayne was such a hero, right?
Wrong: as Ethan Edwards, he's a monomanical racist hell-bent on slaughtering the niece he believes has been dehumanised after she's kidnapped by Injuns.
Influence: Ethan is the sourcebook for the Western's renaissance as psychological warzone, paving the way for the revisionism of Leone and Peckinpah, as well as mapping out a career plan for stars bored of being whiter than white.
Edwards' persona as a troubled soul obsessed with rescuing a damsel in distress also gives him the unusual distinction of inspiring the chalk and cheese of 1970s movie characters: Travis Bickle and Luke Skywalker.
If He'd Never Existed: Movie stars would be stuck playing the hero all the time.