I purchased the FreeAgent 500GB from Seagate as a simple backup for video files. It does that job just fine, and for the price, nothing could beat it.
The speed seems a bit below average, as moving large files does hang sometimes. The ventilation in the unit is next to nothing, with the only airvent on the foot of the device, not where the main body of the hard drive sits. So this thing gets pretty hot.
I'm really not a big fan of the design of this hard drive. It does have a strip of light that pulsates when data is transfering, which is kind of cool, but it is also an ugly orange color. The overall shape of the casing makes it look awkward as well. And instead of the normal USB-B connector, it uses a Mini-B connector, so don't expect to be able to use cables from most other external hard drives.
Overall, it is a decent choice for the price. $150 or lower will get you 500GB and a 5 year warranty, just don't expect it to actually last 5 years.