i've had quantum,maxtor,ibm,western digital and seagate drives.
out of them all i've had no probs with maxtor(now merged with quantum as netman said) and the ibm drives..in fact i've got a 40g Maxtor DiamondMax+ D740X ata133 7200rpm and an 80g IBM Deskstar 120GXP ata100 7200rpm at the mo..
as for the quantum fireball drives i had, they all suffered from overheating...the warranty replacements are in my 2nd pc...at the end of the day you take your chances with any hard drive..