First lady fashion: SamCam and Michelle O stop for a chat outside the White House last night. Photo:Getty
As a nod to her guests, Michelle O opted for a dress by British-born but American-based brand Marchesa - pairing her teal off-the-shoulder gown with a striking Tom Binns statement necklace.
Say cheese: The Obamas and the Camerons arriving at the official state dinner. Photo:Getty
While we're always fans of MObama's style sense, we've got to admit that SamCam may have just pipped her to the post (stylishly speaking) on this occasion...
Which of the glam gowns do you prefer? Vote below!
Go behind-the-scenes at the state dinner preparations here:
Look back at Michelle Obama's European tour wardrobe below:
- Standsted Airport, UK - 26 May 2011<p> With their whirlwind London trip all wrapped up, the Obamas made their final UK appearance at Standsted Airport, before departing for their next port of call: France.</p>

- Standsted Airport, UK - 26 May 2011<p> And we're glad our last glimpse of Michelle Obama on British soil was such a stylish one. Mrs O said farewell in a purple ombre Peter Som dress and overcoat, fastened with a vintage brooch - teamed with patent pumps and a high-shine handbag.</p>

- Winfield House, Regent's Park - 25 May 2011<p> To mark their final night in the UK, the Obamas hosted a formal dinner at Winfield House in Regent's Park - the residence of the USA Ambassador. And it seems as though Michelle saved her most high-octane look for last, stepping out in a gorgeous off-the-shoulder Ralph Lauren gown.</p>

- Winfield House, Regent's Park - 25 May 2011<p> It's no easy feat to out to the Queen in the jewel stakes, but Mrs O gave it her best shot by teaming her frock with this clustered diamond statement necklace.</p>

- Oxford University, UK - 25 May 2011<p> Michelle Obama held a Q&A session at Christchurch College in Oxford University, chatting to girls from the Elizabeth Garrett Anderson secondary school. Mrs O first met pupils from the North London school during her visit to the UK two years ago, and said she was 'thrilled' to be back.</p>

- Oxford University - 25 May 2011<p> America's First Lady paid tribute to the late great Alexander McQueen for her Oxford trip, donning a white bustled shirt from the Resort 2011 collection, with matching McQueen belt.</p>

- Downing Street, UK - 25 May 2011<p> Mrs O is slightly less enthused by the bowl of coleslaw than Mrs C during a barbeque in the Prime Ministerial garden. Her monochrome Tracy Reese dress is better prepared for spillages than SamCam's pastel Jonathan Saunders number, though.</p>

- London, UK - 24 May 2011<p> The First Lady rocks Tom Ford for the royal state banquet at Buckingham Palace. Love the dress, but isn't it a bit bridal?</p>

- Downing Street, UK - 24 May 2011<p> A quick change for Michelle, and the Obamas hit 10 Downing Street for a meeting with David and Samatha Cameron.</p>

- Downing Street, UK - 24 May 2011<p> While Mrs O opted for some block colour-brights in the form of a fuchsia dress and electric purple cardigan, SamCam kept her styling more subtle, in an elegant printed frock.</p>

- Buckingham Palace, UK - 24 May 2011<p> Prince William and his new bride, the Duchess of Cambridge, greet President Obama and wife Michelle at Buckingham Palace.</p>

- Buckingham Palace, UK - 24 May 2011<p> Both First Ladies were looking utterly stylish, with Kate in a figure-hugging nude Reiss dress and Michelle in spring pastels. Even with a world of high-end designer names at her fingertips, we love that the Duchess of Cambridge chose to wear high street for the occasion.</p>

- Buckingham Palace, UK - 24 May 2011<p> We'd love to know what the two First Ladies were discussing inside the confines of Buckingham Palace. Oh to be a fly on the wall!</p>

- Buckingham Palace, UK - 24 May 2011<p> The Queen greets her US guests as they pull up at Buckingham Palace - and was even quaintly co-ordinating with Michelle in her pastel blue print dress.</p>

- London, UK - 24 May 2011<p> Michelle showcases her perfect spring chic while walking with Camilla, Duchess of Cornwall, in a flared prom dress by Brit designer Barbara Tfank and a sweet pink bolero jacket.</p>

- Stansted Airport, UK - 23 May 2011<p> Michelle pulls off some strong colours with this cobalt skirt suit, print blouse and green pumps as the Obamas touch down in the UK.</p>

- Dublin, Ireland - 23 May 2011<p> Michelle wears a graphic print dress with a cream coloured trench and flat pumps for her husband's key note speech at College Green.</p>

- Dublin Airport - 23 May, 2011<p> Michelle wears a monochrome dress with matching shoes. Green detailing features on her belt as opposed to the all-green ensemble Queen Elizabeth II wore for her trip to Ireland.</p>


