Honey, I Blew Up The Kid (1992)
The Original: Late eighties Disney flick Honey, I Shrunk The Kids. Wayne Szalinski (Rick Moranis) is the inventor who accidentally shrinks his kids to the size of ants, then has to find them before they're gobbled up by, well, anything bigger than an ant.
The Radically Different Sequel: Wayne hasn't learnt his lesson, this time accidentally 'blowing up' his toddler so that he's 14 feet tall - and a tantrum-throwing menace to society.
Biggest Change: Well, it goes the complete opposite to the first film. Clever, eh?
If the first film was an ode to the creature features of the fifties, this first sequel is more akin to Attack Of The 50ft Woman.
Waxwork II: Lost In Time (1992)
The Original: A group of teens visit a waxwork museum when it rolls into town. They soon discover, though, that the exhibits might not be all that they seem…
The Radically Different Sequel: Having survived the waxwork museum, Mark (Zach Galligan) and Sarah (Monika Schnarre) discover a strange compass that allows its users to travel through time and space.
Biggest Change: Just about everything.
There are no waxworks in this sequel, the story instead revolving around a series of vignettes, with Galligan and Schnarre taking on different roles throughout. Just… weird.
Leprechaun 4: In Space (1997)
The Original: A young Jennifer Aniston (in her first ever movie role) battles a savage leprechaun (Warwick Davis) who's hunting for his precious pot of gold.
The Radically Different Sequel: The Leprechaun jets off into space and has his eye on a distant planet where he plans on becoming king. No, really…
Biggest Change: The space setting is obviously a bit of a shake-up for the series, but the plot's an absolute minefield of wilful stupidity - just check out the stupid 'Mittenspider' (a doctor who the Leprechaun injects with spider DNA).
RoboCop 3 (1993)
The Original: Paul Verhoeven's breathtakingly violent sci-fi. When Officer Alex Murphy (Peter Weller) is killed by a street gang, he's transformed into the world's first robotic copper.
The Radically Different Sequel: RoboCop (Robert John Burke, replacing Weller) flies into action mode when his partner Anne Lewis (Nancy Allen) is killed. Meanwhile, Detroit goes to hell.
Biggest Change: Aside from the recasting, RoboCop also replaces his hand with a ginormous assault rifle and goes up against robot ninjas. What happened to the gentle nuance of the original film, eh?
Jaws: The Revenge (1987)
The Original: Steven Spielberg blockbuster in which Amity Island is terrorised by a Great White Shark. Police Chief Martin Brody (Roy Scheider) attempts to take the sea-dwelling monster down.
The Radically Different Sequel: Brody's wife Ellen (Lorraine Gary) discovers that the shark terrorising her family is related to the shark that her hubby killed in '75. Yup, it wants revenge…
Biggest Change: The shark, um, has a motive? It also has the uncanny ability to rise out of the water on its tail and roar at people.
Best. Shark. Ever?
Casino Royale (2006)
The Original: Technically, Casino Royale is a sort of prequel-sequel, but it follows Die Another Day, so we'll say that's the original - an increasingly-goofy Bond outing with Pierce Brosnan in the suit.
The Radically Different Sequel: Daniel Craig replaces Brosnan as 007, who's tasked with taking down a weapons dealer. Meanwhile, he falls for Vesper (Eva Green).
Biggest Change: You want a gritty Bond? You got it, as Martin Campbell takes a page out of Bourne 's book for the most daring Bond to date.
The Original: Ridley Scott's Alien , in which Ripley (Sigourney Weaver) and the crew of the Nostromo find themselves trapped aboard their spacecraft with a killer xenomorph.
The Radically Different Sequel: Technically a sort of non-prequel, Scott's return to Alien franchise attempts to figure out the origins of the xenomorph, this time with Noomi Rapace as the lone female survivor.
Biggest Change: The xenomorph glimpsed at the tail-end of the film is totally different to what we're used to, as is the ginormous facehugger.
Omen IV: The Awakening (1991)
The Original: A terrifying religio-horror from director Richard Donner. American diplomat Robert Thorn (Gregory Peck) adopts a young orphan, Damien, who turns out to be the spawn of Satan.
The Radically Different Sequel: We meet young Delia (Asia Vieira), who starts displaying strange powers when she's adopted by Gene (Michael Woods) and Karen York (Faye Grant).
Biggest Change: It totally breaks away (or near enough) from the original film (and its two sequels) for a standalone shocker in which - oh my - the devil child is now a GIRL. Whatever next?
Fast & Furious (2009)
The Original: Mindless action flick in which police office Brian O'Conner (Paul Walker) finds his loyalties to the force tested when he's seduced by the underground world of street racing.
The Radically Different Sequel: A heist movie on wheels as Dominic (Vin Diesel) and Brian are forced to work together to take down a heroin-importing crime lord.
Biggest Change: We still get racing cars and giant action set-pieces, but now the franchise has become more interested in heists than mere petrol-headed thrills - something the following sequels continued.
Mad Max 2: The Road Warrior (1981)
The Original: George Miller's uber-cool road movie starring Mel Gibson as Max Rockatansky. When his family are killed by evil future petrolheads, he sets out for revenge.
The Radically Different Sequel: When Max stumbles upon a small community that's been targeted by bandits for their gasoline, he agrees to help them fight back.
Biggest Change: The first film was more of a bleak post-apocalypse road movie, whereas the sequel puts the pedal to the metal to become one of the coolest action flicks ever made.