which actor has the highest net worth 2018?
['Amitabh Bachchan (net worth: $400 million) ... ', 'Adam Sandler (net worth: $420 million) ... ', 'Mel Gibson (net worth: $425 million) ... ', 'George Clooney (net worth: $500 million) ... ', 'Tom Cruise (net worth: $570 million) ... ', 'Shah Rukh Khan (net worth: $600 million)']