Chris and Annie - Calendar Girls (2003)
Why We Love Them: Friends aren't friends until they've whipped their clothes off together.
Based on the true story of the W.I. members who dropped their threads for charity, Calender Girls is as much a story about Chris and Annie's relationship as it is about the naked shoot that propelled them into the public eye.
They also love chips and think yoga is a waste of time. Perfect.
They say: "We thought if glamour photographers can do it on a beach in Bangkok we can do it in a church hall near Skipton," Chris Harper
Lauren and Sandy - Outrageous Fortune (1987)
Why We Love Them : As with so many great movie friendships, Lauren and Sandy start theirs as sworn enemies, who only meet after they both start dating the same good-for-nothing.
When said bad boyfriend vanishes in suspicious circumstances, the pair join forces to hunt him down, and get caught up in all kinds of escapades along the way (involving everyone from the CIA to the KGB).
They say: "Lauren: You defiled a Christmas tree?" "Sandy: No-one SAW!"
Ellie and Janis - Feds (1988)
Why We Love Them: Determined to prove themselves as FBI agents, badass Ellie and booksmart Janis realise that together they make the perfect cop (if they can survive the tough training and derisive comments of their peers, that is).
Originally written for two men, director Dan Goldberg switched the genders of his stars and inadvertently created a comedy classic.
They say: "Ellie, I had so much fun tonight. We got drunk, we almost got mugged, I met a sailor with a big fish," Janis Zuckerman.
Sara and Maria - Bandidas (2006)
Why We Love Them: Latina uber-babes Penelope Cruz and Selma Hayek joined forces for this Western Comedy about two warring ladies who team up to avenge their fathers and rob a few banks along the way.
It's shameless in its silliness, but doesn't fail to deliver on entertainment.
They say: "I love working with her. She's been my friend for seven years and is someone that I love very much," Cruz on Hayek.
The Sheltons and The Ratcliffs - Big Business (1988)
Why We Love Them: Less double act, more double-double act, Big Business follows mixed-up twins The Sheltons and The Ratcliffs (both played by Lily Tomlin and Bette Midler) as they all visit the same hotel for business.
It's classic farce, and Tomlin and Midler are at their comic best.
They say: "I had known Bette for a long, long time... She is so darn funny, you know?" Lily Tomlin.
Max and Page - Heartbreakers (2001)
Why We Love Them: A mother-daughter con artist duo? There's no way that could go wrong...
It's hardly the greatest movie in the world, but Sigourney Weaver and Jennifer Love Hewitt play on their undeniable chemistry for a few laughs.
They say: "She has a great sense of humour... It was a great, great group of actors," Weaver on Love Hewitt.
Kate and Angie - Baby Mama (2008)
Why We Love Them: The reigning Queens of American comedy, real life BFFs Amy Poehler and Tina Fey always deliver the belly laughs.
Baby Mama could easily have descended into a pointless chick-flick, but the two powerhouse performances gave it emotional levity on top of all the hilarity.
They say: "It was really great to find a role where the women were active rather than reactive,” Amy Poehler.
Ada and Ruby - Cold Mountain (2003)
Why We Love Them: When aimless city girl Ada is left alone during the war to manage an ailing farm after her father's death, it looks as if she's destined to wilt away with her crops.
A concerned neighbour sends no-nonsense Ruby Thewes over to pull Ada out of her funk, and a beautiful relationship begins to blossom, as Ruby takes charge and teaches Ada that there's nothing a girl can't do that a man can.
They say: "Old lady Swanger says you need help. Here I am!" Ruby Thewes.
Lorelei and Dorothy - Gentlemen Prefer Blondes (1953)
Why We Love Them: A breathy blonde and a snappy brunette set out to bag themselves wealthy husbands - it might sound like ninety minutes of gold-digging, but Gentleman Prefer Blondes is unexpectedly pro-woman.
Jane Russell is the perfect foil to Marilyn Monroe, and the pair are so tight they even manage to wangle a double wedding in the end.
They say: "She by the way, was quite wonderful to me," Monroe on Russell.
Lisa and Susanna - Girl, Interrupted (1999)
Why We Love Them: What an entrance. Lisa Rowe (Angelina Jolie) comes bursting through the doors of Claymoore Hospital in a whirlwind of obscenities, kicking and screaming, and from that very moment both the audience and our narrator (and new patient) Susanna (Winona Ryder) are totally bewitched.
The girls go on a journey of self-discovery and rebellion that flips from the comic to the tragic with ease, but it's the nature of the relationship between the leading ladies that really keeps the audience gripped.
They say: "To me she was heartbreaking, and the essence of her was that she wanted somebody to talk to and be a friend." Jolie on playing Lisa.