Yes, I think MC is definitely the role Pacino will most be remembered for. However, unlike some actors, he won't be remembered "only" as a one-time mega hit actor. He has had many outstanding performances besides GF, and they too will go down as work of excellence and I would guess even in years to come film study/actor students will learn much from other Pacino performances.

Marlon Brando the same thing. Not a "flash in the pan", with other hugely successful movies to his credit, that won't be forgotten, he too will be most remembered as Vito Corleone to most.

TIS