Holy ****, I leave the thread for a while and next thing you know people are trying to give Lemieux credit for Selke level defense.
Longtime members of the History/ATD/BTN boards have spent the better part of a decade tweaking a system called vsX which does something similar. Basically it looks at players' scoring as a percentage, relative to the highest scorer in a given year. It can be adjusted to aim at the 1st place mark, 2nd place, 5th place, etc. And you can adjust for outlier seasons when it makes sense to do so. It's sort of a logical conclusion to what you were up to with that list.
Here's the thread with what I think are the most recent numbers -- look at the last page of the thread for results, first page for a detailed explanation of how it works:
http://hfboards.mandatory.com/showthread.php?t=1361409
The bottom line is, as a point scorer Crosby and Ovechkin and Thornton are all in the top 20 all time. None of them are top 10. And Gretzky is just
laughably far above anyone else.