Here's the thing about hard-drives - The more space you shove in them, the higher the probability of a bad sector. At about 4TB levels you're statistically "guaranteed" to have one...
Here's the thing about reviews - The only people that usually spend time writing one are people that are pissed. Not to say that you shouldn't go by reviews, but they aren't as useful as they should be.
I prefer WD. Not that I've had any problems with Seagate (I've never owned one of their drives), but simply because WD has never given me problems.
I have 5 x 1TB WD Caviar Black, 1 x 1.5TB WD Caviar Green, and an old 500GB Samsung (which will soon be replaced with a 2TB WD Caviar Black) in my PC. I have an external 1.5TB WD which has a 1.5TB WD Caviar Green inside...
External drives are not more likely to fail than internal ones simply because they're external like a lot of people seem to believe (not implying that you do). The drives use the same hardware used internally, they just have an additional power supply and different connections. There may seem to be a higher failure rate simply because externals are usually carried around and deal with a bit more wear.
That said, I still recommend WD because I've had a 100% success rate with them.
2TB:
http://www.newegg.com/Product/Product.aspx?Item=N82E168221364711.5TB:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136505On a side note: I ordered a monitor Friday afternoon. Was in my city Saturday morning, and will be in my hands after work.
http://www.newegg.com/Product/Product.aspx?Item=N82E16824001378If I like it, which I'm sure I will, I'll be picking up another for a nice dual setup since I had to sell off my previous monitors and have been using a wimpy 17".
Oh, and a majority of my drives have been running 24x7 for almost 2 years, and they are worked hard by uTorrent. Good stuff, fa sho.