VacMegLev would be the correct answer. It's just the best way to move things, energetically speaking, and by conceptual simplicity. It might be hypersonic planes, though, because all you need is the plane and a blatant disregard for pollution or expense. I really hope not.
Suborbital deserves a mention as a sort of in-between option. It coasts through vacuum most of the way, so between antipodes it might actually beat conventional passenger service, for theoretical cost. I should do some napkin math sometime.