Western Digital WD Blue WD10EZEX 1TB Internal Hard Drive for $54.99 shipped after promo code EMCYTZT5849. Here is a screenshot for reference. It features 7200 RPM, 64MB cache, and uses SATA 6.0Gb/s interface. Note that it comes in OEM packaging, which means no pretty retail box but is otherwise identical. Most places have it for about $59.