God of war collection has sold 1,3m, which is pretty awesome..But could some collection go to over 2m?
I would say some of these has a chance:
Metal Gear Solid collection.
Final Fantasy X-XII collection
Devil May Cry collection
Gran Turismo collection ( if would be released half year before GT5)
Resident Evil collection
Onimusha collection if new Onimusha would be revealed
Silent Hill collection
Kingdom hearts collection
And I don't think "Team Ico" collection or Sly copper collection has a chance.
Take my love, take my land..