Unlike our one-hour dash to the high street, costume designers on film sets have weeks, even months, to cogitate and trial the perfect dress for a party scene.
Short or long? Red or black? Accessories or no accessories? They have the answers perfected.
This might be the reason why some costumes never leave our collective memory, no matter how many years have passed.
They've become a benchmark for the most beautiful dresses and while exact matches are often never attainable, this season it's come remarkably close...
The green gown in Atonement
Eight years ago, we walked out of the cinema after watching Atonement with one thing on our minds, besides that heartbreaking ending - THAT GREEN DRESS. It was long, slinky, bold and elegant all at once in a perfect shade of emerald-meets-shamrock green.
It went on to be named the best film costume of all time and has proudly held the title since. For years we've searched far and wide for a dress that replicated Keira Knightley's costume, but few have come close. That is until now...
Black lace cocktail dress from Pretty Woman
If you google 'Pretty Woman dress', photos of Vivian dressed in a floor-sweeping, off-the-shoulder red gown will flood your page. But in our opinion the most memorable outfit is this lacy black cocktail dress, which she wears to dinner after the hotel manager helps her find an outfit on Rodeo Drive. It's the ultimate transformation.
The black dress in Breakfast at Tiffanys
No black dress says timeless elegance quite like Audrey Hepburn's gown in the opening scene of Breakfast at Tiffanys. It's been copied time and time again and is the ultimate inspiration for simple black party-wear.
Red slip dress, Clueless
A variety of slip dresses dominated Cher's 60-outfit-strong wardrobe. From this vintage red number with spaghetti straps to an iconic white Calvin Klein dress, Cher inspired a trend for slip dresses and spaghetti straps that dominated the late nineties - from the wardrobes of Rachel and Monica in TV show Friends to Laney Boggs' makeover moment in She's All That. And it's still big news today, with a legion of celebrity fans including Rihanna and Anne Hathaway keeping it current.