real hard to say. i have 2 Seagate 640's & 2 Seagate 320's, and a Samsung 1 TB.
the Samsung 1 TB is 5400 RPM. i also bought Samsung about 10 years ago, i have a 4 GB Samsung that has Win 95 and it is rock solid (knock on wood.)
i think they're both good, AND it's important to make sure, if you're getting a Seagate in the 7200.11 series, that you're not receiving one of the disks that had firmware problems and is being off-loaded by some e-tailer.