Seagate - Over the years I've had failures from Fujitsu (?), IBM/Hitachi, WD, and Maxtor.
Percentage-wise I've seen/had several IBMs (all failed within 3 years use), several WDs (but none recently), a couple of Maxtors, but NO Seagates of many used, some for 5 years. I stick with Seagate. No experience with Samsung. I used lots of Maxtors back when WD was having probs with their early 7200 drives, and only two failures out of about 15 after 3-4 years, so they are my second choice. WD is the only drive I've ever owned that failed after only a couple of months, and this happened more than once.
I never use anything near the largest capacities and I always make sure they are installed with room to breathe. I think those two things amke more difference than the brand.
TD