If you have 60-120 thousand USD get yourself setup with the MD3000i SAN. I'd say 100TB of ultra-high speed serial attached SCSI network attached storage should hold you for a while.
A more realistic solution would be to do what I did. Build a NAS. Buy four slow 1TB hard drives, one fast hard drive, and a suitable barebones system (Idealy have at least 6 SATA ports and support RAID 5 arrays on the motherboard). Put it together with the fast hard drive as your system drive, then set the others in a RAID 5 array for nearly 3TB of redundant storage that can survive a drive failure. Cost ~$1500. (A bit more money means you can spring from a PCI-X mobo and a good RAID controller, but not really worth it unless you want RAID 6 with a dozen drives)
The next cheapest solution, is to get an external 1TB drive. Buy more as you need it and pray the drives never fail.
And the worst case solution is burn to DVDs. Verify the burn once completed, and perform yearly backups/reburns.
Or, be a looser and download to watch, then delete. FAIL