Hard drives have become a commodity and they are largely all the same due to consolidation on the low end. You'll still get a bit better quality if you step up to a raptor, etc. But all of them have a fairly high failure rate now.
Dont keep anything important in only one place.
Or do like I do, get yourself some of these:
http://www.drobo.com
I absolutely LOVE that device. I've lost drives inside it twice and never lost a byte of data. Just eject the faulty one, insert a replacement, it does the rest.