All the celebrity fashion from the Costume Institute Ball 2008

It's the fashion world's answer to the Oscars and the biggest red carpet night in New York's social calendar, which is why everyone who's anyone in fashion flocked to the Costume Institute Gala at Manhattan's Metropolitan Museum last night.

Co-hosted by Giorgio Armani, US Vogue's Editor Anna Wintour and George Clooney and Julia Roberts, this year's event had a superhero theme to mark the launch of a new exhibition at New York's Metroplitan Museum, 'Superheroes, Fashion and Fantasy'. And it was definitely a night for fantasy fashion.

Topping all the best dressed lists, Kate Moss arrived looking fresh faced and fabulous, hand in hand with designer pal Stella McCartney. Both were stylishly flying the flag for British fashion in two of Stella's own creations. Also stunning, Christina Ricci channelled the Wonder Woman vibe in a sheer pink Givenchy gown which revealed her red superhero leotard underneath.

Stars at the ball are invited as guests of designers, so there were plenty of fashionable pairings for the night. Karl Largerfeld was escorted by his date actress Diane Kruger, Eva Mendes attended with Calvin Klein's Creative Director Francisco Costa and Liv Tyler (both in Calvin Klein), Claudia Schiffer arrived in Valentino with Mr Valentino and a newly engaged Scarlett Johansson left fiance Ryan Reynolds at home for the night to party with her pals Domenico Dolce and Stefano Gabbana (will her wedding dress also be Dolce?)

Those who didn't arrive with their designer hosts brought their own partner's in crime, dressed in matching outfits of course. Husbands Tom Cruise and David Beckham willingly sported Armani tuxedos to match their wives (Katie Holmes and Victoria Beckham - as if you need telling) Armani gowns while fashion's dynamic duo Ashley and Mary Kate Olsen paired up in Diane Von Furstenberg gowns designed especially for them by DVF herself.

Click here to see all the stars on the Costume