As far as internal drives, I recommend Seagate, because they offer the longest warranty by far on consumer drives. Seagate offers 5 years, all the others just 1-3 years, which I think says something about their own confidence in their quality.
Note that Seagate, etc all offer just 1 year on their external drives, so if you're the handy type, you might want to consider buying your own empty FireWire enclosures and installing your own internal drives into them.
tooki