For a properly dressed crab I insist you visit Corrigans of Mayfair. Now he may be a Mick, but he can cook. He once prepared me a crab which brought me to tears.
There is plenty to be said for a devilled crab Mornay, of course.
He's a charming fellow. I approached him once in the street and gripped his hand. "Mr Corrigan," I said, for 'twas he. "I just want to take this opportunity to thank you for so many incredible meals." He looked duly pleased and said something unintelligible in that approximation of the English language you people use.