Western Digital Black
WD Black is a series of more expensive harddrives from Western Digital.
 Lifetime expectancy
A WD Black 640 GB produced in October 2009, bought early 2010, died a horrible clicking death on August the 9th 2017.
While the disk itself was dead the smartctl information remained accessible. smartdata story is that 'Error 49 occurred at disk power-on lifetime: 49836 hours (2076 days + 12 hours)'. This is five and a half years of continuous pretty demanding use before failure.
It's up to you to judge if this is good or bad. It is clearly much better than Seagate which makes drives that fail after just a few months.