Seagate Barracuda 7200.10 (Perpendicular Recording) ST3320620A 320GB 7200 RPM 16MB Cache IDE Ultra ATA100 Hard Drive $89.99

Perpendicular Recording increases data density while decreasing moving parts for a more dependable drive.
Adaptive Fly Height offers consistent read/write performance from the beginning to end of your computing workloads.
Clean Sweep automatically calibrates your drive each time you power up.
Directed Offline Scan runs diagnostics when storage access is not required.
Seagate SoftSonic motor enables whisper-quiet operation.
Enhanced G-Force Protection defends against handling damage.

Newegg is carrying this 320GB Hard Drive for $89.99 + Free Shipping