Depends on the HDD's being compared and then there's the concern of reliability. For speed comparisons see -> http://www.harddrivebenchmark.net/high_end_drives.html
Yeah, prices now 'suck' and the projected stabilization of Supply and Demand goes through the end of 2012 i.e. high prices for a year+; Thailand flooding + mergers.
I only use 1TB 7200 RPM HDD's 'on consumer PC's' and for quality and RAID, WD consumer lines lack TLER, I recommend the SAMSUNG Spinpoint F3 HD103SJ 1TB 7200 RPM 32MB Cache - http://www.newegg.com/Product/Product.aspx?Item=N82E16822152185
though I've been looking at the Seagate Barracuda ST1000DM003 1TB 7200 RPM 64MB Cache - http://www.newegg.com/Product/Product.aspx?Item=N82E16822148840
since Seagate took over Samsung's HDD production.