Michelle Obama has topped the first ever Sunday Times Best Dressed list.

The United States' first lady was commended for using fashion as a ''force for good'', while other names on the list included Queen Elizabeth and Home Secretary Theresa May.

The Sunday Times Style magazine described Michelle, 49, as ''understanding that, as her primary role as first lady is visual, fashion can be a force for good used to inspire and entertain.''

56-year-old politician Theresa was also praised for having ''the best legs in the cabinet''.

Other names who made the top 25 include Spice Girls singer and fashion designer Victoria Beckham, artist Grayson Perry's drag alter-ego 'Claire', Shiloh Jolie-Pitt - the six-year-old daughter of Hollywood stars Brad Pitt and Angelina Jolie - and actress Dame Helen Mirren.

Tiffanie Darke, the Sunday Times Style magazine's editor, said: ''The diverse nature of this list demonstrates the importance of fashion in the overall conversation, confirming the role clothes play in creating a visual manifesto.''

''What's so encouraging is that among the 25 people celebrated today, no two share a similar look; they all occupy a different part of the fashion spectrum, using their own taste and judgement to bring together an individual style that serves to inspire.''

Meanwhile, singer Lady GaGa earned the dubious distinction of being named Worst Dressed by the magazine's editors and contributors.