Scoring 80 goals in one complete season, regular season + playoffs, has occurred 14 times in history (all since 1971).
Of the 14 occurrences:
4 x Gretzky
2 x Bossy
2 x Lemieux
2 x Brett Hull
The other four, who each did it once, are Jari Kurri, Alex Mogilny, Teemu Selanne, and Reggie Leach.
The "90 in total" club, in order:
100 - Wayne Gretzky 1984
97 - Wayne Gretzky 1982
97 - Mario Lemieux 1989
97 - Brett Hull 1991
90 - Jari Kurri 1985
90 - Wayne Gretzky 1985
It seems odd that there's such a drop from fourth to fifth and sixth.
(Fun to speculate how many goals Gretzky would have had in '84 if not missing six games, and Gretzky, Lemieux, and Hull in their 97 goal seasons if their teams hadn't crapped out in the first or second round.)
By the way, who had the most total goals (RS + playoffs)in a season, pre-expansion?