i have used & managed many hdds seagate, fujitsu, ibm(old now owned by hitachi), samsung, maxtor,wd, hitachi(old & hitachi storage system), quantum(old now owned by maxtor), & excelstor(i bet many haven't even heard about it) except one compaq 9gb 7.2kprm scsi, ata drives, from 2gb to 250gb
currently, i like samsung & seagate.
unlike pre 1999 samsung models, they are very reliable from my experience + service is excellent. from models introduced 2002 or later, they perform very well especially with 8mb models. new 2.5" 7.2krpm 80gb models are super fast(i bet not many even heard about 2.5" samsung drives) cool & silent when running in silent mode, but even with performance mode, they are quiet; i can recommend samsung; for company i work, i recommend samsung; i use 4 ata 160gb 8mb models for my personal pc as a raid 5; up & running 24/7 for last 14 months without any problems
for seagate, 7200.7 plus does not perform as well as wd or maxtor or samsung(8mb), but sata version is fast especially with new 200gb model; 8mb retail version carries 3yr warranty; sata version is only native sata queuing supported drive on the market; seatgate claims that 37gb raptor is not faster than 200gb 7200.7 plus drive in terms of server performance
problem with wd is that the spindle servo is very noisy at least most of them; some with fdb servos (jvc) but most don't & new version with 8mb & fdb servo is called pb not jb; shows jb model's age, bit slow
maxtor seems have 3yr warranty for 120gb or larger 8mb models but when i called the;m maxtor carries 1yr for all models. i think all plus models come with fdb motors, thus, quiet