I have bought quite a few Maxtor USB/FireWire external hard drives in the last few years. There's not much to say about them. MTBF has not been stellar.
I don't know which brand I want next, but I do know that I want eSATA.
definitely seagate.
I had too many broken/corrupted maxtor drives. I have a Quantum drive thats old though and is still going.
Never used Samsung but the one in my Xbox died..