At time of writing (May 2011) there are currently a total of 66 5 Star Hotels in London.
I have complied a top 10 list which weighs up reviews vs. Prices to give you best value for money;
The Milestone Hotel: From £300 per night
Hotel 41: From £299 per night
The Soho Hotel: From £331 per night
Sofitel St James London: From £212 per night
Andaz Liverpool Street: From £169 per night
Hotel Verta: From £127 per night
Brown’s Hotel: from £351 per night
The Dorchester: from £306 per night
Four Seasons Hotel London at Park Lane: from £392 per night
Claridge’s: from £290 per night
Depending on what you are staying for should dictate which hotel you choose. If location is an issue obviously choose a hotel which is centrally located but it is isn’t an issue I suggest you stay further from the town centre as prices inflate on a logarithmic scale. The Hotel Verta is exceptional value with rooms always available under £200 (Around Olympic Dates would be pushing it) but if money is no object there are hotels like the 4 seasons which will still make you raise an eyebrow.