[BwanaNdege]

Greenland - (840,004 sq. miles) (2,175,600 sq. km)
New Guinea - (303,381 sq. miles) (785,753 sq. km)
Borneo - (288,869 sq. miles) (748,168 sq. km)
Madagascar - (226,917 sq. miles) (587,713 sq. km)
Baffin - (194,574 sq. miles) (503,944 sq. km)
Sumatra - (171,069 sq. miles) (443,066 sq. km)

[KarlInOhio]

I'll check the ultimate reference for all continental questions: the map from Risk.

Greenland - part of North America.
New Guinea - part of Australia
Borneo - part of Australia
Madagascar - part of Africa
Baffin - part of North America
Sumatra - part of Australia
New Zealand - doesn't exist

[dangus]

I referenced Madagascar because whereas Greenland, New Guinea and Borneo are connected to North America, Australia and Asia by submerged continental shelves (like Great Britain is to Europe), Madagascar is on a separate hunk of granite altogether from Africa... although in double-checking myself, I was surprised that there is indeed an “ocean” between much of Greenland and Baffin Island, North America, and the continental connections between them (on either side of this “ocean”) are much smaller than that between Alaska and Siberia.