OSL-HEL-BKK,HAN-NRT-HAN,KUL-MNL-SYD,BNE-SYD-AKL-LAX,LAS-MIA-LHR-OSL in GC Mapper (may not have go this correct)
And in Mileage Monkey (click ignore errors - MM is not up to date) http://www.slfft.org/mm/award.htm?ow...R-OSL&cabins=y

For max mileage instead LAX,LAS-MIA-LHR people here would go LAX-MIA-LAS-LHR. That is go the long way and not the short most direct way
Similarly SYD,BNE-SYD-AKL-LAX could be re jigged for more miles
From SYD you can get 1 flight number to JFK or DFW (more miles)