I'm using the Maxtor 40 gig 740dx series drive and like it alot. Maxtor has probably one of the most reliable drives in my opinion. A good friend of mine who works in the field and knows what hard drives last said WD drive quality has been lacking and he replaces them alot along with the Seagate drives. Actually, not that this is one of your choices, but I have 2 Samsung 80 gig SP8004H hard drives for storage and they are a GREAT bang for the buck and my friend says Samsungs have always been very reliable. Also, they offer decent performance. According to storagereview.com though the WD drives are at the top for performance. I'd go with the Maxtor though. Just my 2 cents.