I’ve been watching this brand of Autosport more intensely over the past few weeks. Everyone I think will agree that the start of the season has been pretty bumpy for some, great for others.
But I haven’t been watching long enough to know the driving skills of the “oldies” (G. Villneuve [sp?], A. Prost, Fangio)…
I know that it is difficult to compare racing car drivers from different generations, for various reasons e.g. the technical aspects of the car change so much…
So I’ll simply ask in your humble opinion, who was the greatest Formula 1 driver of all time, and why?
Jackie Stewart.
He ruled F1 when he was driving and he retired at the height of his game.
Not a big follower of F1 but it is a form of motorsport. I refuse to call it auto racing though. And the evolution of the cars used in F1 makes comparisons between those of the past and current drivers a moot point. No one won a F1 championship by fluke, any past champion would be considered a very good driver. Here is a list of past F1 champions. If he was still alive, Airton Senna would probably be known as the best of all time. As far as wins and championship, no one has topped Michael Schumacher, the current champ.
I’d have to say Fangio, but I have kind of a weakness for the old days, when drivers were fat and tires were skinny. Do a web search and see if you can find a good account of the 1957 German Grand Prix.
Damn, I want to drive the Nurburgring someday.
Fangio, of course, with Prost, Stewart, Senna, and Schumacher also ranked high, and an honorable mention to Mario Andretti, who might have been better than everyone else had he concentrated on F1.
Fangio going away.
Part of greatness must be measured by competition. Fangio faced the stiffest competition; Moss, de Portago, Musso, Taruffi eg.
There are several more modern drivers who are quite good, but will never be Juan Manuel.
Andre Di Chesaris. anyone who can drive the wrong way around Silverstone is genius. 
I am. Alas, no one will ever truly know the depth of my abilities.

Actually, being involved in a number of motorsports in a purely recreational fashion, I just can’t fathom how these guys can do what they do with the reflexes they must have.