I have a fairly good impression of Caviar Green. However, you must note that they are EARS drives, which use some different kind of formatting (which resulted in these bad reviews that kita mentioned), so you will have to look into that if you intend to utilize the full 2TB (if you ignore it, I think you only get 1.4TB or something). They are also designed to spin down during long idle periods to conserve energy, so their response time is a bit slow at times. Definitely do not use one as a boot drive. Otherwise, for storage that you access infrequently and don't need fast response times for, it's pretty good. 64MB cache is relatively decent, as most HDD caches these days are 32MB or 64MB.
I probably shouldn't recommend a drive I've never used before, but meh. Just want to throw that out there, since I've done a bit of reading on them and most people haven't.
Do read reviews, and pay no heed to those that complain about the lack of space, which take up a good chunk of the bad reviews. As per usual when looking at HDD reviews, also ignore DOA reports and such, as shipping is not always smooth and DOAs will occur here and there no matter how well the drives are packaged.