Quoting General Keebler

I always thought that a DVD would last longer than a hard drive (assuming you treat it well)... am I mistaken?

In any case, I'd think you'd want to do something about the VHS first, since I'm nearly positive that that will last the shortest of the three (But even that should be good for 15 years minimally I think).

actually, I would definitly think a VHS tape would last much longer than *recordable* DVD or CD, why? Because a Recordable DVD/CD has the dye in it that will "go bad" or turn or whatever. I have many VHS tapes that are 25+ years old, some older, that are still fine. VHS tapes are more likely to wear with use rather than "age" as some have noted. Kinda like a trade off. VHS will wear the more you use it, recordable DVDs wont. However, a VHS tape wont have any dye that will "wear out" because its store magnetically.