For me the forgotten player of Australian football who was at a time, world class or borderline world class was Tony Dorigo, who actually still to this day calls himself Australian.
Was named in PL POTS, won player of the season at Aston, Chelsea, Leeds and Torino. Played in a world cup 3rd place playoff and had it nkt been for Stuart Pearce who was the best or 2nd best left back in world football at the time, would have played 60 + caps for England.
Anytime i see a former leeds player pick their best 11 hes always in it.
Id also argue that Cahill, Bosnich and Viduka for brief points were also considered world class.