With this question you will always get mixed results, purely because there will always be flaws in manufacturing processes that will undoubtedly mean there will be bad batches. And an unhappy customer is always louder than a happy one.
Thus, there will always be horror stories from every HDD manufacturer out there.
Personally I prefer Western Digital, purely because I've had several drives from them and never had any issues. Personally I will also never touch Maxtor or Seagate - I've had 2 of each in the past 3 years and each of them have given me issues (slow transfer speeds, clicking sound of death, insanely bad spin-up times (eg, 4-5min for my external Maxtor to spring to life after puting my PC to sleep).
Though there will be someone on the other end too... someone who has had nothing but trouble with western digital, and will rave till the cows come home about how awesome Maxtor is.
Really it comes down to your own history with the brand in question.
Im a WD & Samsung guy. I will always avoid Hitachi, Seagate and Maxtor, purely because of my bad history with their drives.