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I own a LaCie drive, and it's been great for me. In the year and half that I've had it, I haven't had a single problem with it.

I haven't ever owned a Seagate drive, though, so I can't speak to their quality.
 
Seagate makes great hard drives as well and usually have a really good warranty plan. You probably can't go wrong with either one. Just comes down to the money.
 
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