Idk. Both are great but pacino is only defined by one role while de niro has had more defining roles. They both have had a lot of terrible roles. But I'd say if both of their careers ended after the 90s or even before the 90s started, De Niro would be seen as the better actor. De Niro I would put in the top 3 all time idk if I would put pacino up there. I think the main reason they're always compared so much is because they came up at around the same time and they're both Italian americans who have played mobsters.