I think half the people here would swear by Seagate and the other half with WD.
I have been using "Segate Baracuda" 40 GB HDD for past 8 years and there is no issues. I bought samsung 160 GB HDD about 3-4 yrs back it is always having some issues, heat and bad file descriptor.
I know that WD is famous for 10K RPM, but not sure about its reliability and service.
I am not sure about how good it is in > 1TB segment since I am not using it, but from what ever info i have from online views and word of mouth from my hardware friends, it is the De facto leader in HDD arena in India. Hence I would suggest do no compromise for any other HDD model. The 7200 RMP model has been very popular so far.