Something struck me the other day in my regular quest to compile F1 trivia: Lots of drivers have won WDCs with different teams but only Fangio and Schumacher have won more than one WDC with more than one team - and in the latter's case he took a lot of personnel from Benetton to Ferrari with him.
This got me thinking, who have been the best drivers (other than above) at moving teams? Prost must be there - three WDCs with McLaren, a WDC with Williams and almost two WDCs with Renault. Piquet too, multiple WDC with Brabham, one WDC with Williams and nearly another.