If you are looking for speed, I suggest the Maxtor Diamondmax Plus 2500 10gig. It runs at 7200rpm, and is alot quieter then my WD Caviar 6.4gig. The 2500 is every bit as fast as An IBM 14GXP, if not faster. I have seen some reviews that even have it outperforming 10000rpm Cheatahs in SOME tests. The best part is that I got mine for like $225. Just look at pricewatch.
We've experieced failed WD Caviar 1.2Gb hard drives in less than 2 years. But in both incidence, we were able to get replacements from WD and they replaced them with brand new 3.2Gb. Go with a company that will warranty them for 3 years and replace them with brand new drives. Some companies will send refurbished ones, so beware.
I've sold hundreds of these drive - usually the IDEs 'cept for the IBMs. They're all good brands, though I've been having problems with the Seagates the past year or so. I think encountered these when they moved their main plant in Asia to China, the Conner factory which I heard they bought. There was a time when 60% of their drives failed. Fujitsu is not the fastest drive around but they sure are reliable, say a 3-5 percent failure rate. But I'm biased towards the Quantums, starting with the Bigfoots. A friend accidentally dropped one and gave it a dent but the drive still worked w/o a hitch, 'course I won't warranty drives with external physical damage. The Fireball EX/EL with SPS are good buys, they're my top choice right now for IDEs.