I have a 2TB Hitachi Deskstar that I used for games and other general storage, and it suddenly died on me (it tripped SMART with "Seek Error Rate"). The three choices I have within a sensible budget (no Caviar Blacks or Barracuda XTs) are another 2TB Deskstar, a 2TB Samsung Spinpoint F4 and a 2TB WD Caviar Green. Of the three, which one should I use to replace the Deskstar?
The deskstar is a 7200rpm drive, the other two are lower-speed low-power drives. That's the largest difference between them. If it's the OS drive, I'd go with the deskstar. Otherwise, choose based on whether performance or low power / low temperature are more important to you.
Other than hearsay, there's nothing to distinguish these drives in terms of reliability. It will be easier to keep the lower-speed drives cool, so that might help.
Here's some hearsay: I've been using WD Green drives for quite a while now, including two 2GB drives I purchased about three months ago, and have been quite happy with them. I use them as bare drives in a USB drive dock, so cooling isn't an issue for me. They get handled a lot more than an internally mounted drive would, but that hasn't caused any problems so far.