The Most Long Lastingest Storage?

What digital storage can retain information the longest? Recordable CD/DVDs only last a couple of years. A decade at most. Barring catastrophic disk failures, HDs seem to last the longest, but what about Flash Memory? These types of memories are increasing in capacity rapidly and they don't have any moving parts.

Not to rain on one's parade, but isn't the advantage of digital media the fact that you can copy it? Why worry about media that lasts eternally when you can just make a bunch of copies, and them make more down the road?