I have used all types of drives in my various system.
Currently, I am using WD Raptors as boot drives, WD 500GBSE16 drives in RAID 1 as data drives in my Mac Pro, and have Hitachi 500GB in my Infrant ReadyNas NV+ which is on 24/7 gets used almost as much, it's my back up, streaming media, ftp, and NAS for my home.
The Hitachi in the NAS are OEM, and have been installed for about 1 year now without a single hick-up. When I am not home, and I shut the A/C off, they run at about 110F and not one failure.
The WD drives in my MacPro are the same: reliable and fast. Only have had them installed for about 2 months, and no failures.
The new Seagates .10's are good drives. I would use them without hesitation.
In the past, Samsung drives have had a bad rep. Bad QC, lots of failures. But, I think they fixed these issues, they have been highly recommended, and lots of positive reviews on them. I just have no current experience with them.
Hitachi's had a bad rep in the past, when they were IBM drives. The current crop of Hitachi drives are excellent.
If you are concrened about warranties, and 3 years is not long enough for you, buy an enterprise rated drive, they usually come with year warranties. I only by OEM drives, and have never had a warranty problem with WD, Hitachi, or Segate.
So, buy whichever drive is within your budget. Shop around, and you should find some great deals.
Basically:
Capacity you need
7200 RPM
16MB Cache
SATA 3.0