The fact the original post do not mention Bobby Hull (one of the most mainstream candidate for that title) didn't bold well to not have it turn into some Crosby vs Ovechkin affair.
It will be a hard debate because it depend how much peek, prime, career are weighted and that change from person to person and there is no undeniable number #4 forward unlike the top 3.
During Hull nhl career:
http://www.nhl.com/stats/player?agg...r=gamesPlayed,gte,1&sort=points,goals,assists
http://www.nhl.com/stats/player?agg...r=gamesPlayed,gte,1&sort=points,goals,assists
He outscored is competition both in regular season and the playoff quite well, 604 goal to 463 for the closest and 1153 above an aging Gordie Howe at 1060. 129 points to Beliveau 122.
The point finish (Crosby still 2 season to play)
Hull : 1,1,1,2,2,2,4,5,6,7,9
Crosby: 1,1,2,2,3,3,3,3,5,6,10
With 3x Ross, 2x Hart, 7 Rocket would trophy existed, great career in the WHA after the NHL, not impossible for Crosby to reach him if he age like a Sakic/Jagr/Yzerman/Bourque type of aging well player, but he is still not there yet imo, even if he had the career start to make it possible (specially if he would have played more during is peak) and is play rely a lot of is strength and stamina, you can keep strength quite well but will see, making league top 10 is already a challenge for him by now.