Most sights in London (The Big Ben, The London Eye, Buckingham Palace, Hyde Park, The British Museum) are located within Zone 1 as well as other well-known places such as Piccadilly Circus, Oxford Street, Kensington High Street. If you wish to find cheaper long-term accommodation, the best choices are Zone 2 or 3. In case you are travelling as a tourist, Zone 1 is certainly the best option.