Seagate Barracuda ST2000DM001 2TB 7200RPM Internal Hard Drive for $109.99 shipped.  Here is a screenshot for reference.  This drive features 7200RPM (much faster than 5400RPM drives), 64MB cache, and 1TB/platter design.  It comes in OEM packaging, which means no pretty retail box but is otherwise identical.  Most places have it for about $145.