I worked in computer retail. I also did 2 years as the faculty manager and another 6 years as faculty advisor for a student-run computer lab that deployed about 250 new computers every fall. The computers were set up to automatically reformat and rebuild themselves every night. Maintenance was our biggest cost, and part failures went in this order: keyboard, mouse, CD-ROM, power supply fan, hard drive.
All hard drive brands have weak batches. I can remember when I specified IBM drives for 2 years because the drives were great, fast and dependable! And then came the year of the 36GB / 40GB Deskstar... I have never replaced so many drives in my life.
Does anyone remember the Quantum Bigfoot? One year our Purchasing Office 'simplified' our RFP and we got 200+ machines with Bigfoots in them. I really wanted to hate those machines. I really really wanted to hate those drives. I wanted to kill everyone in Purchasing and drink their blood. Sadly, to this day, we still talk about how amazingly, freakishly dependable those stupid Quantum Bigfoots were. Slow, yes, but most of the computers were used for MS Word, and the techs came to love those drives...
All brands have good and bad batches, but that said, I have always hated Maxtor. Through the Pentium years Maxtor was tweaky, and they seemed to get worse as they aged. And during the early years of 'autodetect' Maxtor drives would commit seppuku if the BIOS didn't get the drive information right.
For myself, I use Western Digital. I have no proof, but IMHO Western Digital seem more tolerant of being 'handled' - being swapped from computer to computer, riding around campus on repair carts, being constantly reformatted, etc.
My biggest criteria for any computer component is the ease of warranty service. Thats why I buy from Newegg. Thats another reason why I prefer Western Digital.
It's also why I buy eVGA video cards - I just got a new eVGA 8800GTS, and in several places inside the box it says, in large red print, that if the card is defective, do not return it to the retailer, but instead contact eVGA directly by web or phone for RMA information. It's bad if a product breaks, but eVGA knows that if you, the customer, have something break, and you have a good experience getting it replaced, that you'll probably buy that brand again. Because stuff breaks - no manufacturer is perfect.
If a hard drive manufacturer had a RMA process whereby I could send in the serial number of the drive and they would automatically approve me for replacement parts based on manufacturing date, and where they would cross-ship if I provided my credit card, I would immediately switch to that brand.