I saw a review of 2TB hard drives recently, either here at THG or Anandtech.
The Western Digitals and Samsungs did quite well. Personally, I'd be partial to Western Digital, they seem to get it done right the first time, their warranty processing is reasonable. Overall, they seem to be the ones that offer a decent drive with the least amount of fuss. Samsung is good but I've heard that filing a warranty claim on their drives is a pain - I cannot give any details on that since, though I own 4 samsung drives, I have not had to file a warranty claim.