You probably don't plan to drop your drive before installation or scrape your shoes on the carpet and zap its controller card with a spark of static electricity, but these things happen more often than you think--and they can damage the new drive. Drives in the accompanying chart are covered by warranties, but there's no way to reimburse you for time--and, maybe, data--lost from an installation gone wrong.
Consider a drive rated to withstand at least 150 Gs (Gravity Force units), which should cover the typical low-level drop. Seagate's new Barracuda ATA does that one better; it is completely encased in an aluminum SeaShield that gives it the ability to withstand 300 Gs of shock and helps keep errant static discharges off its circuit board.
PC problems in other areas can sometimes show up as drive troubles later. Vendors report that more than half the drives returned to them are working fine. To head this off, most brand-name drives include software tools to help you ascertain the condition of the drive before it's yanked and sent back.
Quantum's Fireball LCT line includes its Data Protection System, a comprehensive diagnostic suite that's embedded in the drive. Western Digital, Seagate, IBM and Maxtor have diagnostic routines of their own. And all of these manufacturers' drives include SMART technology, which uses predictive failure analysis to warn you about impending problems. This information can be read by a third-party program like Symantec's Norton SystemWorks 2000 or LAN administrative tools.