I agree completely with buying in the sweet spot. However, I have (& have had) enough drives in play to say without any question that WD's fail more frequently and more catastrophically than any other brand. I personally liked Maxtor but I believe they've been bought out by Seagate, which is not that bad. Seagate customer service is much easier and faster to deal with when there is a problem.
WD has always wanted the end user to download a diagnostic program and then supply the results prior to issuing an RMA. I still remember the first drive I had that died and not only could I not download the software, but the drive was not even being acknowledged in the CMOS. The guy made me setup the drive as a slave and run the diagnostics (which would not recognize the existence of the drive) before issuing an RMA.
On future drive issues, I was able to solve this problem by telling the customer service rep that the drive has flames issuing from its case and please excuse me for a moment while I extinguish them. Only then would they issue an RMA without running the diagnostics...