Western Digital RED most definitely IMO for that purpose. Amazon and Scan were offering the best prices recently, but check Ebuyer too.
The WD Greens have had some intellipark issues and the RED does not use this, they are quieter and use less power than the Greens and are the latest technology but designed for NAS. They do cost a little more but I think they are the ones to beat at the moment for the use you want.
There are lots of reviews, pretty much all positive.
http://www.expertreviews.co.uk/inter...igital-red-3tb
http://www.silentpcreview.com/WD_Red