will depend on what you want to do. is it for backup in the event of a recovery, or are you planning on 'archiving'? Disk will be quicker to recover from in case you lose a file(s), but tape will allow you to retrieve 'archived' or different versions of stuff that you've saved (i.e. music, movies, formal/legal documents) because the cost of storing 'archived' is cheaper over all.
With tapes you can store terabytes under your desk, on a shelf...in a safe under the house etc. With disk, you need to power it and have a connection to it... you could store USB drives
in a safe under the house, but then why not use tapes if you're going to be doing that?
Here's a Quantum one:
Here's a HP one: