It really depends on why you're archiving, I guess.
Professionally, full quality versions are archived onto LTO tapes and are constantly updated, depending on how rapidly new LTO versions get released. It's also becoming increasingly common for all the associated files to be archived as well (ie: project files, edit sequences, original unused takes, EDLs etc).
OR
Are backed up onto film negative.
If you just want a copy of your film that will last, export a full quality version (whatever that may be) and upload it to the cloud in a few different places - maybe somewhere like Mediafire. Keep a copy on a drive and on a Data DVD or Blu-Ray, as well as a playable DVD or Blu-Ray. Update archives as necessary (ie. transfer to new archive drives once your archive drive is x years old).
Also, archiving to tape is not a bad idea either - HDCAM SR is expensive but great quality. DVCPRO HD is less expensive, still great quality, though perhaps less abundant these dasy.