[Roanon]

Of about 100 hard disks I bought/sold I had 2 failures (after about 4 years of service) - both in the early days of HDs, both cheap ones - plus one 6 month old Maxtor Last year.
I also always advise to let them run rather than switching off the computer if it is for just a few hours or less. Energy saving settings for HDs are deadly. Usually HDs running 24/7 are the most reliable.