The main two are Tube and Bus and they perform slightly different functions. Buses are 'short hops' and Tubes are 'long hops'.
Bus - If say you're travelling down Oxford Street, then jump on a bus and 'hop' a stop or two which can take less than 2 minutes. It saves the feet.
Tube - is better to travel between zones - say you're in South Ken. and visiting the museums and you want to then go to Covent Garden - you'd use the Tube. It can make that journey quickly, but by bus it would be slow as you have to traverse the traffic hotspots in Hyde Park Corner, Piccadilly Circus, etc.
Try the river too - you can get travel cards which include the boat services and the DLR (Docklands Light Railway) is light and airy and is included in Travelcard coverage.
More tips here #mce_temp_url#
Patrick
