Originally posted by iTim:I wouldn't go for anything less than 1TB. I currently have a 500GB Seagate portable hard drive which has run daily without any issues for the past six years. I also have a 2TB Western Digital desktop drive (requires power) which I use for backing up my media collection. I've not had a single issue with either drive over the years that I've had them.
Decide what you want to store on the drive and then decide how portable you want it to be. Generally speaking, a 2.5" portable hard drive will be powered by USB, making it easy to move around. A 3.5" external drive will require another power source in order to operate, making it less portable.