samsungs are quiet, but i received a faulty vibrating one.
maxtors are dodgy - 2 of my friends drives died within a year
i have a seagate and its been perfect. its not as quiet as the samsung when seeking but i tend to prefer being able to hear what my HDD is doing. gives me a heads up if something is going on that i dont want to be happening etc.
ive read that weston digital arent great reliablilty but really cant comment.
ive read that the hitachis are good, but again, cant comment as i have no first hand experience.
if i was to buy another drive, it would be a seagate.