Seagate Desktop HDD.15 ST4000DM000 4TB 5900 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive - £66.99 (44% off) - Newegg

[KevinP]

http://www.newegg.com/global/uk/Product/Product.aspx?Item=N82E16822178338&ignorebbr=1

If you're looking for some mass storage drives, here's a good value 4TB HDD