A classic that's as popular now as it was in the 20's, this spot in chichi Mayfair is the epitome of elegance. The Art Deco details are sublime, as is the pricey afternoon tea (though it's as much a people-watching exercise as an indulgent experience). Big draws here are the Michelin-starred Gordon Ramsay restaurant (the city's toughest booking) and the gorgeous Fumoir bar, which harks back to the days of flapper girls and jazz piano. Add neo-Art Deco suites fashioned by David Linley, and a stay here is like stepping back into the long-lost glamorous days of travel.
Insider Tip: Register for a master class with executive chef Martyn Nail; he covers such gustatory topics as traditional British cooking, canapés, and carving (appointed Saturdays, 11:30 a.m.2 p.m.; $300, including tutorial, lunch, and coffee).
Room to Book: Piano suite. It comes with butler service, a bottle of Laurent Perrier Brut NV, an outfit pressed when you arrive, and of course, a grand piano. They're all complimentaryafter, of course, the $6,300-a-night price tag.