Hi,
Hitachi for me. I got 3 Hitachi DeskStars (all different models, all in different PCs) and they've never failed me. One of them I've had for 3 years now and it's still as healthy as it was when I bought it.
Then I've got a Samsung SPN (some numbers after it, can't be bothered to take the PC apart to find out what they are) which I detest, bought it last year and it's already losing speed. It's spin-ups take forever! The PC will pause for about 20 seconds at times to spin the disk up.
And I had a Maxtor drive a while ago which broke on the 3rd or 4th month from the purchase date. I couldn't find the flipping receipt for a refund either =[
Anyways, I like Hitachi drives.
-Luke.