I've used a handful of Seagate Barracudas, and they've worked quite well. I've also had external FreeAgent drives, all of which lasted a few months before dying. So, I guess I got lucky with the Barracudas I've used.
My advice is to get Seagate drives from retailers that offer good warranties (IDK what kind of warranties Seagate offers, but I'm not too confident in the quality of said warranties), and then test the heck out of them before storing important data on them. If they fail, that's where the warranty comes in. I would probably store copies of whatever the heck you feel like putting on the HDDs, and then re-formatting them. Repeat this process for at least a few weeks, and see what happens.