The Metropolitan line should be the fastest. They are capable of the highest speeds. The second fastest is Central, third fastest is Jubilee, and other fast lines are Victoria and Piccadilly. Circle line is the slowest of all.
The Central Line
The Northern Line.
The Circle Line.
District Line (London Underground) from Hammersmith tube station to Victoria tube station.
Camden
Camden
The Central line is the current oldest tube stock in the whole of the London Underground.
The Circle Line Unfortunately this answer is wrong! According to Transport for London the only tube line to connect all London Underground lines is the Jubilee Line.
Depends on the context: London has a tube (Metro) line which is called the Circle Line.
Redbridge on the Central Line - which is also coloured red on the tube map.
Presumably you mean the London Tube? If so, it is the Jubilee Line (silver).
About 45 minutes by Tube. If there are no signal failures on your line.