Which Hard Drive is better

Western digital is more reliable in my experience. Alienware uses them, when I bought one in 2000. Bought a segate External HDD, crapped out on me in the 1st month.

You've linked to two different Seagate drives..

Anyway.. I've used both the Seagate Barracuda 500GB as well as the Western Digital 500GB drives and the WD win hands down. My Seagate was loud (for a brand new drive) and died within months of installation. I RMA'd and the second died within 5 weeks! I had bought these drives from ebuyer, and with their amazing customer service allowed me to change the second RMA request so that I got a WD drive instead - Never had a problem since!

Infact, I now use three WD 500GB drives.

You can get a WD 500GB drive from ebuyer at around £50 ($76, €55)

Dont you just love Western Digital?

Yes.

Currently, If I were in the market for a drive, I would get either a WD Caviar Black or a Seagate 7200.12. The other WDs are good too, but I wouldn't get a Seagate 7200.11 (they've had a lot of problems with this line) or 7200.10 (loud, relatively slow - they are quite reliable, but older generation drives, and are no longer worth it)

Yeah... I went with a 1Tb caviar black.