I used to swear by Maxtors, myself. I've got them in four different machines right now and they're running great. (These are all older IDE drives though. Haven't used their SATA drives.) One the other hand, I had a one of a pair of 160 GB Maxtor drives fail on me after only three months. (Luckily I was using them in RAID 1, so I didn't loose anything.) The little research I did at the time seemed to think the general quality of Maxtors had gone downhill in the last year or so. That's the first one I ever had fail.
On the other hand, I've had several WD drives fail. I've had several that didn't, too. One place I worked bought a batch of HP Pavillions that had WD drives in them. Over the first six months almost half of them failed. HP sent our tech guy a new case of WD drives to replace the remaining ones. The replacements did fine though. I also found WD drives to be noisier in general.
Now, I'm using Seagates exclusively -- at least until they start failing on me. They're very quiet and very fast. I've use a bunch of the SCSI drives in the day, and they only seemed to fail when they were ancient.
Case: Enermax CS-A106USB
P/S: OCZ OCZ700GXSSLI 700W
Motherboard: ASUS P5N32-E SLI
CPU: Intel E6300(idle 35C/load 39C)
RAM: OCZ Platinum Rev 2 DDR2 800 MHz (4 x 1GB) 4-4-4-15-T1 (2.1v)
Hard Disk: Seagate 2x250GB SATA ST3250620AS in RAID1
Monitor: Mitsubishi DP900u
Graphics: BFG GeForce 8800GT PCI-E
Sound: SoundBlaster X-Fi Fatal1ty
Speakers: Klipsch ProMedia v.2-400 4.1 speakers
Optical: LiteOn 16X DVD-ROM; Sony DRU-710A DVD-RW