Dumb & Dumberer: When Harry Met Lloyd (2003)
The Prequel: Ever wondered how two idiots like Harry and Lloyd possibly found each other? Well, it all started in a Special Needs class in the 1980s…
Why It's Grim: You want dumb? You got it. This lazy cash-grab is resolutely bad taste and - its greatest crime - completely unfunny, mistaking stupid for side-splitting. This is the kind of film that actually makes you loose IQ points as you watch.
Worst Link To The Original: Harry and Lloyd like riding vehicles together, normally to hilariously messy ends.
The Flintstones In Viva Rock Vegas! (2000)
The Prequel: When Fred, Wilma, Betty and Barney go on a trip to Rock Vegas, Wilma's courted by smooth operator Chip Rockefeller (Thomas Gibson).
Why It's Grim: It's recasting ahoy, with John Goodman et al replaced with budget TV versions in the form of Stephen Baldwin (no, really) and Mark Addy. Jane Krakowski is a rare bright spot as Betty, but otherwise this is insultingly moronic stuff.
Worst Link To The Original: Everybody sings 'Meet The Flintstones' at the film's close, reminding us how good the cartoon really was.
Casper Meets Wendy (1998)
The Prequel: Everybody's favourite friendly ghost makes a new friend - and it's giant-mouthed Wendy (Hilary Duff) who's the witch for the job.
Why It's Grim: It's typical straight-to-video fare. The special effects are rudimentary at best, the story as twee as that scarf your nan knitted you. It's also really, really boring.
Worst Link To The Original: Instead of Casper's evil uncles making an appearance, we get Wendy's three intolerable aunts…
Transmorphers: Fall Of Man (2009)
The Prequel: Set 300 years before the masterpiece that was the first Transmorphers , this cheap-and-cheerful prequel was a product of The Asylum - which tells you everything you need to know about it.
Why It's Grim: Well, it's a product of The Asylum… If you thought Transformers: Revenge Of The Fallen was bad, you ain't seen nothin' yet.
Worst Link To The Original: The atrocious CGI 'transmorphers', which look like something a 12-year-old created on their computer.
Butch & Sundance: The Early Days (1979)
The Prequel: William Katt and Tom Berenger play the titular duo in their youth, long before they turned into Robert Redford and Paul Newman.
Why It's Grim: It's a fluffy, throwaway romp with zero emotional impact as Butch and Sundance get caught up in numerous scrapes. When something's this forgettable, you start wondering why anybody bothered making it…
Worst Link To The Original: The duo's jaunts include, yes, more train robbery. Sigh.
Amityville II: The Possession (1982)
The Prequel: The Montelli family move into that creepy house, but pretty soon young Sonny has started acting strangely…
Why It's Grim : It steals wholesale from The Exorcist and Poltergeist , but skips any theological questions by going for dumb shocks instead.
That said, it's better than the original, which has to count for something…
Worst Link To The Original: The entire film is a rehash of the first film, but with added gore.
Cruel Intentions 2 (2000)
The Prequel : Started out as a pilot for a proposed Cruel Intentions TV show, but when the series got dumped, the pilot was released as this choppy embarrassment of a prequel.
Why It's Grim : Sure, Amy Adams gives good bitch as Kathryn, but it's not hard to see why this never made it to series.
It's basically a cheap copy of the brilliantly snide original - and thanks to the last minute edit job that turned the pilot into a movie, the plot also makes no sense whatsoever.
Worst Link To The Original: Any of the PG-13 sex scenes, which just whiff of desperation.
National Lampoon's Van Wilder: Freshman Year (2009)
The Prequel: Time is rewound as we meet Van Wilder (Jonathan Bennett) during his freshman year. Cue parties galore and more raunch than you can wave a spank paddle at.
Why It's Grim: For a start, the timeline doesn't make any sense - if the first Van Wilder was set in 2002, surely this prequel should be in the '90s? That makes the presence of mobile phones very confusing. This is dumb comedy at its dumbest.
Worst Link To The Original: The reliance on doggy bodily fluids for laughs. Or not.
Wrong Turn 4: Bloody Beginnings (2011)
The Prequel: College kids (this bodes well) go on a snowmobiling trip, but they get lost in the blizzards and become cannibal fodder. Sound familiar?
Why It's Grim: The actors all seem to have taken lessons from Joey Tribiani, there are random and insulting lesbian scenes presumably inserted to titillate teenage boys, and nobody even seems to care when they friends get brutally hacked to pieces. Horror with no stakes is poor horror indeed.
Worst Link To The Original: It's another group of college kids vs cannibals. Ho hum.
Joseph: King Of Dreams (2000)
The Prequel: Set before the events of The Prince Of Egypt , this low-rent animation follows Joseph (Ben Affleck), who is given a technicolour dream coat.
Why It's Grim: Have you seen it? The animation's two-cent dreadful, the songs are little more than a raucous din, and the plot succumbs to sappy sentimentality at regular intervals. Steer clear.
Worst Link To The Original: Um, it's set in Egypt?