Simon Radley at the Grosvenor

Simon Radley's formal restaurant (you're instructed to arrive 30 minutes early for drinks and canapés) has served near-perfect Modern British cuisine since 1990, when it was first awarded the Michelin star that it has kept ever since. The food is divine and the wine list extensive. It's one of Britain's best, but why no second star? Note that attire must be smart and no children under 12 are permitted.