I'm a big fan of WD black drives, good performance and never had any issues. However the reviews of the Samsung Spinpoint F4 sound pretty amazing and they're cheap too. (320GB for 43$)
86$ for 640GB Raid 0.
55$ for 500GB storage. (WD Blue or similar)
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141$ - 1,1TB
or
129$ fpr 960GB Raid...