For the record, here's more or less what I'd use for an all-time ranking:
60 points for a Tour win. 20 and 12 points for 2nd and 3rd, 6 points for a stage, points jersey or KOM jersey win
45 points for a Giro or Vuelta win. 15 and 9 points for 2nd and 3rd, 4.5 points for a stage, points jersey or KOM jersey win
40 points for a Worlds or Olympic RR win. 10 and 6 points for 2nd and 3rd (think its fair to have placements count less in a one-day race)
30 points for a monument win (so that all 5 monuments = all 3 GTs). 7.5 and 4.5 points for 2nd and 3rd.
15 points for the other main one-day races. Difficult to agree on which races should count, I'd go with:
Bordeaux-Paris (until 1980, to mirror its fall and the introduction of San Sebastian)
GP des Nations (until 1993, the final edition before the TT became a Worlds discipline)
Züri Metzgete (until its final edition in 2006)
Paris-Tours (until it wasn't included in the WT, so until 2011)
Flèche Wallonne
Gent-Wevelgem
Amstel Gold Race (from 1966)
Clasica San Sebastian (from 1981)
Worlds TT (from 1994)
Olympic TT (from 1996)
Strade Bianche (from 2012, mirroring Paris-Tours)
15 points for the main smaller stage races:
Paris-Nice
Tirreno-Adriatico
Euskal Herriko Itzulia
Tour de Suisse
Critérium du Dauphiné
Peace Race (until the fall of the Wall)