I've used Western Digital, Samsung, Seagate, Maxtor, JTS Corp, and IBM drives - that I can remember now anyway - haven't had many problems. I have had RMA experience with WD and Samsung:
Western Digital: the drive kept shutting down and resetting itself. RMA'd it - easy to do; gave them CC#, they sent me a refurbished drive drive, I installed it, and found it was doing the same thing. I sent back my drive anyway, and kept the refurb'd - once I got a new power supply, everything worked fine. Oops.🙁
Samsung: Someone just decided to give me a dead 20GB drive he had laying around awhile. Warranty was still good - RMA'd it, got a new drive, sent the old one. The drive's worked just fine for me.
My main system has an IBM 120GXP main drive and a Seagate Barracuda secondary drive; the video station system, which is nearly as powerful as my main system, has 2 Western Digital drives in RAID 0, and a third, smaller WD drive as extra storage.