Well, like the title says, who is the driver you consider as the best "Rain Master" of anyone else? When I say "Rain Master", I mean drivers who drive particulary well in wet weather.
'm sure the first names that come to mind are Senna and Schumacher. But for me, it's Welshman Tom Pryce. Mainly because he qualified in Pole, in a car only capable of a mid-field position, for the 1975 British Grand Prix, the qualifying session itself was played out in wet weather. Another notable wet weather session was when Pryce finished ahead of everyone by a large margin during a practice session for the 1977 South African Grand Prix, the same weekend that took the Welshman's life after colliding with a 19-year old marshall at over 170 mph.
In my opinion, Pryce isn't usually considered as a "Rain Master" by many F1 fans in my age group (15-17) because hardly anyone has heard of him!
Anyway, as I said, who do you consider a best "Rain Master"?