Mickey Mouse (Steamboat Willie)
Impact: Steamboat Willie , the first widely distributed Mickey Mouse short, revolutionised animation by adding sound to the mix.
But it was the character at the heart - loveable but cheeky, a Chaplinesque Everymouse who couldn't help but get into trouble - who paid off Walt Disney' mortgage.
Influence: As the cash cow that made the Mouse House possible, Mickey's influence is as much economic as artistic.
Yet there's no denying that his DNA is seen in just about every mainstream 'toon character since, whether the animators are aping him or subverting the template.
If He'd Never Existed: Chester J. Lampwick would be a millionaire. Uh, that's right, isn't it?
Vito Corleone (The Godfather)
Impact: Until The Godfather , gangsters still conformed to the rat-a-tat street hustle of Cagney, but Vito's stay-at-home crime boss, running an empire through sheer force of personality, astounded audiences.
It's all in the contradiction of a family man, proud as punch on his daughter's wedding day, who agrees to have a henchman decapitate a horse as a favour to a friend.
Influence: Vito left us wanting to know more about how a man could be so benign and yet so terrifying, so Coppola duly obliged by showing us his roots.
The crime genre remains in thrall to Coppola's model of seeing what's behind closed doors. Martin Scorsese's made a career out of it.
If He'd Never Existed: There'd be no reason to keep orange peel.
John Rambo (First Blood)
Impact: Rambo wasn't the first on-screen Vietnam vet to make a splash (that'd be Travis Bickle) but Sylvester Stallone's less complex, more direct anti-hero captured the Zeitgeist.
Saved from death by test screening audiences, Rambo proved to be the enduring poster boy of Reagan's America, a one-man army who could get the job done.
Influence: Stallone's model begat Schwarzenegger, Seagal, Van Damme and the rest, turning 1980s video stores into specialist retailers of testostorone-and-ammo porn. And, as Stallone's adventures in recent years, you can't keep a tooled-up muscleman down.
If He'd Never Existed: It wouldn't be enough to start an acting career simply by being a Hollywood agent's martial arts instructor.
Hannibal Lecter (Manhunter)
Impact: It took two attempts to make Hannibal the Cannibal the leading bogeyman of the past two decades. Brian Cox's cerebral turn in 1986's Manhunter was overlooked, leaving Anthony Hopkins to essay a more personable, professorial take on terror.
Menacingly nimble in face-chewing action and yet strangely endearing, Hopkins as Lecter was so memorable he won an Oscar for 16 minutes of screen time.
Influence: Screen baddies got sophisticated, with mind games replacing brute force as the modus operandi of the cinematic psycho: Keyser Soze, John Doe, even Scream 's pub quiz killers.
Hannibal himself couldn't be kept down, with The Silence of the Lambs getting a sequel and two prequels.
If He'd Never Existed: We wouldn't be scared of joining Mensa.
Ellen Ripley (Alien)
Impact: The terror of Alien came - in part - from genuinely not knowing who would survive, such was the lack of stars and uniformly intense character actors who populated the Nostromo.
But making Sigourney Weaver's Ripley the lone survivor was a masterstroke, redefining the macho sci-fi genre with a feminist icon who could be both fragile and hard-as-nails.
Influence: Weaver herself was the most immediate beneficiary, becoming the '80s go-to girl for Hawksian heroine-ism.
But the female action hero lived on via Linda Hamilton's Sarah Connor, Geena Davis in The Long Kiss Goodnight and pretty much anything Angelina Jolie has done since Tomb Raider .
If She'd Never Existed: The typing pool would offer better prospects for actresses than Hollywood.
King Kong (King Kong)
Impact: A giant monkey swatting planes away from the Empire State Building was always going to be exciting, but what nobody counted on was that people would cry when he died.
Influence: Actors, smactors. Who needs to bother with dialogue when a lump of plasticine can convey the emotions just as well?
If He'd Never Existed: Rubber masked mimes arsing about on cardboard models would be considered the cutting edge of FX.
Norman Bates (Psycho)
Impact: If it's not bad enough Hitchcock has us rooting for a guy who's accessory to murder, it turns out he's the perp all along.
The startling narrative switcheroos of Psycho still work because it's scarcely conceivable that mild-mannered, jittery Anthony Perkins could be a knife-wielding maniac.
Influence: Before Bates, evil was a shadowy affair, but suddenly it could exist in the most banal locations possible.
The slasher icons inspired by Bates might have reverted to hockey-masked ghoulishness, but the real creativity of the character is manifest in the films of David Lynch.
If He'd Never Existed: We'd all get on with our neighbours.
Rick Blaine (Casablanca)
Impact: Humphrey Bogart was already putting his on-screen career as a hoodlum behind him when he was cast as Casablanca 's cynical bar owner, but it's the ambiguity that defines the character.
A textbook example of how to layer a character, Rick's redemption is all the more satisfying because he's so close to being an outright bastard. Is he a hero? A villain? The film keeps you guessing to the last reel.
Influence: More so than any of the hard-boiled 'tecs, it's Rick who defined the tortured heroes of film noir, and became the model for the grumpy anti-heroes of the beloved 1970s - Jack Nicholson's best roles, for example, have something of Rick's yin and yang.
If He'd Never Existed: Black is black, white is white and there'd be no surprises hidden in the shades of grey.
James Bond (Dr No)
Impact: Blasting his way directly into the audience's own gunbarrel, 007 hit the target straight away. Audiences were shaken - and indeed stirred - by the secret agent's combustible blend of sex, violence and humour.
Influence: Even setting aside the six actors who have played Bond in the 22 official films, James Bond's thoroughly modern adventuring set the mood for every action hero who followed. Quips, gadgets, women and an enviable sense of style.
If He'd Never Existed: The Cold War would still be going given that, without Bond, the Soviets probably think they stand a chance of winning.
The Tramp (Kid Auto Races At Venice)
Impact: Seismic. Until Charlie Chaplin donned bowler hat, moustache, tattered coat and baggy trousers, cinema lacked a defining character of its own, favouring theatrical stereotypes or real people going about their business.
By stripping things to basics, the archetypal underdog figure powered only by mime, Chaplin changed the rules and became the movies' first global superstar.
Influence: Incalculable. Chaplin couldn't escape the Tramp's distinctive silhouette, returning to the role until the late 1930s. But more than that, The Tramp's bittersweet charm prefigured every comedian since, while his athletic derring-do arguably paved the way for action cinema.
If He'd Never Existed: We wouldn't be watching movies today.