It would be my pogoplug with a Drobo. Then I would have the RAID backup and expandable, able to get to it anywhere in the world, sharable AND the best part is that I don't have a monthly service charge. The cheapest way you're going to get storage bytes is with your own HDs but you want to make sure they are redundant.
Of course if you want to make sure they can withstand a fire then you need to get them offsite or make up some fireproof contraption for your Drobo. :-)