Jacques Anquetil was the first (1957, 1961-1964) He also won the Giro d'Italia twice, and the Vuelta a EspaƱa once.
He was followed by Eddy Merckx (1969-1972, 1974), Bernard Hinault (1978-79, 1981-82, 1985), Miguel Indurain (1991-1995), and then Lance Armstrong (1999-2005).
Indurain was the first to win it five times in a row, followed by Armstrong with seven in a row.
The question of the greatest rider of these is relative. Riders like Armstrong and Indurain were specialists, who pretty much focused on the Tour (with a couple of exceptions, like the Amstel Gold Race for Armstrong, for example).
On the other hand, riders like Merckx and Hinault raced all year long, racing not only the tour, but other races that the likes of Armstrong or Indurain would have never done - Paris-Roubaix, and many other one day events.
My nod goes to Merckx and Hinault.