Eugene from Storage Review has compared a bunch of 250GB HDDs.
As of this writing, the 250 gigabyte capacity point represents a sweet spot at which consumers receive the most space per dollar spent. All five major SATA manufacturers offer a 250 GB model with a street price that hovers around $100.
All drives in this roundup feature two or three platters and incorporate a native SATA interface running at either 1.5 or 3.0 Gb/sec (remember, however, that this figure represents a ceiling rather than achieved rates). Some manufacturers outfit their budget-oriented drives with 8 megabytes of buffer while two have doubled cache to roomier 16-megabyte standard.
He checked out the Hitachi Deskstar T7K250, Maxtor DiamondMax 10, Samsung SpinPoint P120, Seagate Barracuda 7200.9 and WD Caviar WD2500KS HDDs. You can check out the roundup over here.