I’m coming due SOON for a hard drive upgrade in my MacBook Pro (120 GB. just isn’t enough anymore…) so I’m up in the air as to which of the brands above I ought to go with and why I should pick that manufacturer over the others? The R/R looks to be easy enough that I can do it myself (clone the current internal to the new one while it’s in an external enclosure then physically swap the drives) but since my machine is 3 years old a little freshening-up is in order. FWIW, while a SSD is intriguing, my budget isn’t anywhere close to letting me buy a 250GB+ SSD so I’m sticking with a conventional 7200 rpm drive.
for laptop I would get a WD at this point ?
scorpio Black model (320 gig) ? might as well get more performance out of your book that you can and this will help some I just put one in our knock around laptop and it helps out some
in truth all HD companies have had ups and downs and certain HDs in certain sizes have had more issues than others so you just have to try to sift through some new egg reviews and keep your ear out to certain problems
I have about 35 TB worth here at the house of mixed brands and over my years in computers have had all brands fail at one point or the other
I do say make sure you always have a bu or a clone using something like Carbon Copy Cloner or Super Duper for a bu of your system drive (in a laptop this will be your main HD) that way you can be back up and running quickly if something goes south
one other thing I tend to do is when I expand storage I will get a opposite company for BU so if my main working is a WD I might use a Hitachi for bu (BackUp) this way if a certain HD starts to have later failures and turns out to be a issue chances are my BU hard drive wont fall into that ?
At least once a week I do a full bootable clone of my internal drive to an external and then every ~6 months I burn my iTunes and iPhoto libraries to DVD’s and stick them in the safe. Were the house to burn down I can always rebuy apps but it would nearly kill me to lose all our photographs.
Personally I like the Seagates as they have the longest warranty on them.
I have had to replace 2 Hitachi’s, one under warranty and one out of pocket.
I have WD that started making a bearing noise just after it was out of warranty. I looked around the net and found this was a common issue for WD.
When I went shopping for drives, IT friends said to stick with WD when available. They gave me several geekly reasons why that my eyes glazed over during. My hardware and networks run well, so I’m inclined to listen to them.
Go for the Western Digital Scorpio Black if it is compatible with your hardware. Their 250 GB drive (5 year warranty) is $65 on newegg.com
Seagate used to have the lead, right now Western Digital is leading the pack.
Both Seagate and Western Digital offer 5 year warranties on their better drives.
There was a period of time (more than 5 years ago) when WD drives lacked in quality, Seagate went through the same thing after they bought Maxtor (known for hard drive failures just out of warranty).
had a 500gb Seagate portable USB drive go Tango Uniform after a week. Plugged in the drive and the computer saw it, and there was no partition. They did warranty it and luckily I had backed up my backup 3 hours before the drive sent south.
For laptop / portable hard drives it is worth it to get a drive with a drop sensor as well, most have them these days.
The drive can handle a much heavier jolt when it isn’t operating.
With external drives it can be the enclosure or the drive that goes bad.
No matter what brand I go with I had figured on sticking with my current backup plan–a couple times/week I run a full bootable clone to an external drive and burning my photo/music libraries to DVD ~every 6 months. The 120GB drive I currently have as an internal drive on my MBP will go into an enclosure to become a second external drive that I’ll probably use for more offboard storage or “Home” folder backups that will also go in the fireproof box Mrs. JV and I have. Either way, if the new internal drive has a catastrophic meltdown, I’m covered.
I would bu daily rather than once a week 
you can schedule it to do it for you so you never have to remember ?
I personally use time machine and a clone setup but my living is made off a computer doing photography so I cant loose any time
I currently use SuperDuper! and since I’m still on the free version, backups happen when I remember to start 'em (if I had the pay version, I could schedule them every day if I wanted).
one thought is to also try out time machine ? depending on your work habits ? if you are moving the laptop around keeping a HD attached to it will be a pain 
as I say the best plan is one you will actually do !
if you can afford to miss a week of stuff then once a week is OK ?
I think the one problem most have is they make some things to complicated etc…
If you are moving from the original 5400 RPM drive to a 7200 RPM drive, make sure you update the system firmware.
As shadowalker suggested the Scorpio Black is pretty much the fastest and has a shock sensor. If you are searching there are still some models that only have 8MB cache, the new models have 16MB cache. Do not get stuck saving a few bucks by buying the older model.
[ul]
[li]Performance
[/li][li]Lowest power consumption
[/li][li]Solid company/warranty
[/li][li]Price
[/li][/ul]
IMHO WD is the BCM/Noveske of Hard Drives…but I am biased.