Samsung F series drives are good, not expensive, and reliable. I've had IBM/Hitachi drives fail a lot(had a box of about 10 failed IBM drives) and some WD and Maxtor drives fail. I have had no Seagate or Samsung drives fail so far.

made this a poll

Seagate. It's reliable. (Not when your drive is 7200.11).

what about 7200.12?, that's what my 500gb drive in the server is atm

7200.12 is very very good. I'm still having that one. But I cannot use it because my computer is broken (CPU fried).
Everyone knows what happened to 7200.11.

Most of the failed hard drives that I have come by have either ben the Hitachi desk/Travelstar series, or seagate. I have seen only one WD fail. I personally have 2 Seagate Barracuda's that have gone bad on my server(good that I have a bare metal recovery). In my opinion WD is the best

I recommend seagate is the best have used 3 seagate drives over the past 10 years 20gb, 250gb and 1TB drives and all are still working, whereas I originally had a 20gb wd in my oldest pc which failed after 3 months.