These are the generational talents in hockey:
Orr
Gretzky
M. Lemieux
Crosby
Ovechkin
McDavid
That's it. Maybe toss in Gordie.
Step function level of outperformance relative to your peers from day one - that is generational and it doesn't happen often. The word needs a real f***in' rinsing in hockey. It's super cut and dry to me.
On the goalie side, it's probably just Dryden, Tretiak, and Hasek.