Cloud backup service Backblaze uses tens of thousands of hard drives (41,213 as of December 31, 2014, to be precise). Last year Backblaze published the hard drive failure rates it experienced, and it just updated those numbers with data from 2014. The chart above sums up the results.
The bottom line: if you want great reliability in a desktop hard drive, you probably want a 4TB hard drive from HGST (1.4% failure rate) or Seagate (2.6% failure rate).
Now, this survey probably is not totally scientific, since it depends on what Backblaze has in its data center. But it is probably the best data available on hard drive failure — especially at this kind of scale.
(via Ars Technica)