1Tb Hitachi Deskstar 7K1000.B SATA-2 Hard Drive 16MB Cache. These are probably the best make of hard-disk currently on par with the Samsungs for speed and reliability, yet often found at good prices like this. Not sure if Quidco is available with Aria, but they are a good seller in my book.
£61.99 after delivery + hidden VAT fees. Cheaper at scan.
£59.99 @ eBuyer (with Free del option): http://www.ebuyer.com/product/150256
[And no, this is not a self-promo!]