Definately avoid Fujitsu and Hitachi hard drives. I've heard the following models are the best hard drives. In my opinion would pick from the below models listed and no others.
Western Digital Raptor
Quantum Fireball
Maxtor Diamond Max (not the Maxtor Plus 8 or Maxtor Fireball)
Seagate Barracuda
Samsung T-series
Western Digital Caviar RE
I just bought an 80 gigabyte Serial ATA Barracuda hard drive yesterday.