I've purcahsed 3 Maxtors and 3 Lacie (I needed larger then 300).. All the Maxtors ran trouble free for a few years. I think 4, 3.5 and then I traded the other one.
I've sent my Lacie drives back 3 times for replacement. The Lacie Firewire/800 adapter I purchase also failed. Basically 4 purchases from Lacie and 4 failures
My next external purchace will be SATA RAID and I'll build it using Seagate drives.
If I needed just a 300G external I'd probably buy 2 Maxtors. 1 for the data and 1 for the backup.