Kate Middleton, Duchess of Cambridge, was out and about all weekend celebrating Prince Philip's 90th birthday in some fabulous clothes. But, not to be ignored, Pippa Middleton also has a unique style of her own.

While Kate wears regal and royal hats and has been known to wear the same outfit in public more than once, Pippa has a laidback yet classic style, perhaps because she's not in the limelight as much as her sister.

Pippa shined in a chic white gown at her sister's wedding to Prince William in April, but Kate looked equally as stunning in her white, lace Alexander McQueen wedding gown--perfect for the young woman who was about to become a duchess and wife to a prince.

While Kate was attending a charity gala in a gorgeous light pink gown, Pippa took in some tennis wearing a white linen dress and a jean jacket.

So it begs the question, which sister has the best style? Or are the too different to compare?

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Kate and Pippa
A schoolteacher has bought Kate and Pippa Middleton's childhood home Reuters
Kate Middleton
Kate Middleton attends Prince Philip’s 90th birthday. Reuters.
Pippa Middleton smiles during the match between Andy Murray of Britain and Janko Tipsarevic of Serbia at the Queen039s Club Championships in west London.
Pippa Middleton smiles during the match between Andy Murray of Britain and Janko Tipsarevic of Serbia at the Queen's Club Championships in west London. REUTERS
Most charismatic public appearances of Kate Middleton as Duchess of Cambridge
From left to right: Britain's Catherine, Duchess of Cambridge leaves St. George's Chapel, with other members of the royal family, after a service to mark Prince Philip's 90th birthday, in Windsor, west of London June 12, 2011; Duchess of Cambridge waves to the crowd as she sits in a horse drawn carriage with other members of the royal family as they make their way to Buckingham Palace after attending the Trooping the Colour ceremony in central London June 11; Catherine meets U.S. first lady Michelle Obama at Buckingham Palace, in London May 24, 2011; Catherine, Duchess of Cambridge arrives for a charity dinner at Kensington Palace in London June 9, 2011. REUTERS
Britains Prince William and his Catherine
Britain's Prince William and Kate Middleton visit Witton Country Park in Darwen, northern England April 11, 2011. Reuters
Catherine
Kate Middleton smiles during a Naming Ceremony and Service of Dedication for the Royal National Lifeboat Institution's (RNLI) new Atlantic 85 Lifeboat, the 'Hereford Endeavour', at Trearddur Bay Lifeboat Station, in Trearddur Bay, Anglesey in north Wales February 24, 2011. REUTERS/Dylan Martinez
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