I've only ever used Western Digital drives, but never had any problems. My history:
WD 8G (1997?)
WD 25G (1999?)
WD 80G Caviar (2001)
WD 200G Caviar (2003)
WD 250G Caviar (2004)
The only one that has given me any problems was the 80G I bought right before I went to Japan. I packed my desktop well, but I still worried it wouldn't survive being dropped, thrown, banged, or whatever else happens to airline baggage. It's traveled in boxes and suitcases like that from US->Korea->Japan->US->Japan->Korea->US, and still works. However, after the last trip, I noticed that every few weeks or so it would cause the computer to hang continuously in 1-2 second intervals when reading files. Rebooting always fixed the problem, though. This slowly got more frequent, and occasionally it would make a horrible pinging noise. That was kind of unnerving, but I was able to keep using it for months up until I replaced it. I was able to copy all my data to my new hard drive, save 200K lost to bad sectors. Still, considering the circumstances, I think that drive was quite the trooper.