FYI, the best 50 drivers from 1950 to June 2001, according to win percentage, in my opinion, the best indicator. This are my own calculations, I will update them another day.
I know Schumi is better right now (does anybody knows how much?)
Pos Driver GP Wins Win%
1 Juan Manuel Fangio 51 24 47.1
2 Alberto Ascari 33 13 39.4
3 Jim Clark 73 25 34.2
4 Michael Schumacher 145 44 30.3
5 Jackie Stewart 100 27 27
6 Alain Prost 201 51 25.4
7 Ayrton Senna 162 41 25.3
8 Stirling Moss 67 16 23.9
9 Damon Hill 122 22 18
10 Nigel Mansell 191 31 16.2
11 Tony Brooks 39 6 15.4
12 Giuseppe Farina 34 5 14.7
13 Niki Lauda 177 25 14.1
14 Jacques Villeneuve 82 11 13.4
15 Mika Hakkinen 148 18 12.2
16 Nelson Piquet 207 23 11.1
17 Jack Brabham 128 14 10.9
18 James Hunt 93 10 10.8
19 Alan Jones 113 12 10.6
20 Jim Rathmann 10 1 10
21 Jochen Rindt 62 6 9.7
22 Emerson Fittipaldi 149 14 9.4
23 Mario Andretti 131 12 9.2
24 Jody Scheckter 113 10 8.8
25 Gilles Villeneuve 68 6 8.8
26 Peter Collins 35 3 8.6
27 David Coulthard 107 9 8.4
28 Ludovico Scarfiotti 12 1 8.3
29 Rodger Ward 12 1 8.3
30 Carlos Reutemann 146 12 8.2
31 Ronnie Peterson 123 10 8.1
32 Graham Hill 179 14 7.8
33 Froilan Gonzalez 26 2 7.7
34 Denny Hulme 112 8 7.1
35 Wolfgang von Trips 29 2 6.9
36 Jacky Ickx 122 8 6.6
37 Mike Hawthorn 47 3 6.4
38 Peter Revson 33 2 6.1
39 Phil Hill 50 3 6
40 Piero Taruffi 18 1 5.6
41 Johnny Surtees 113 6 5.3
42 Giancarlo Baghetti 21 1 4.8
43 Gerhardt Berger 210 10 4.8
44 Dan Gurney 87 4 4.6
45 Rene Arnoux 164 7 4.3
46 Didier Pironi 72 3 4.2
47 Luigi Musso 25 1 4
48 Keke Rosberg 128 5 3.9
49 Bruce McLaren 104 4 3.8
50 Pedro Rodriguez 55 2 3.6