Been watching since 1954 so can judge most of F1 great drivers.
Not much doubt of the best that was Jim Clark, simply a genius, closely followed by Fangio & Senna. Moss also ranks up there being able to win despite driving inferior machines. Schumacher can also be mentioned in the same breath as those but few others can.
Moss didnt win a championship & most agree he was amongst the best when people with very little talent like Hunt & Damon Hill did win it so statistics dont always tell the whole story because the car plays a large part.