vote for seagate
why?
my maxtor 40 gb which i have used for 6 years until now is still working fine ,
same as @andyKCIUK which has used it for 8 years
wdc is about performance
but seagate is about lifetime
I had a 20 GB WD back when 20 GB was quite big and found it a big hassle. Three days after I installed Windows on it I begain getting idiot errors and crashes. I reformatted and it worked perfectly - for three days - and then the same problems. I went back to my 8.4 GB as C: and that drive as D: for music and video and had no problems until I retired it. It seemed as if it couldn't handle sudden access and quick writes. No wonder they are cheaper!
Are not Maxtor drives now branded Seagate since Maxtor was bought by Seagate a few years ago? I have 3 250 GB Maxtors which all still rock! I had problems with one of them but it was because I had three installed close to each other and vibrations from the other two were throwing it off. It works fine again now that I've reformatted it and I'm now using it in a toaster.