I'd suggest WD1001FALS drives. That's the Caviar Black 1TB, consumer version. It's $100 these days at Newegg.
The WD1002FBYS is basically the same drive, but optimized for RAID and for 24/7 operation and tested more thoroughly. It costs $160.
The difference is negligible in normal home use, and it comes mostly from better tolerance to vibrations. That is, if a truck passes in front of your home, the regular drive may lose the track and waste 4 ms to find it again, while the RE3 drive has a better chance to avoid that. That's the theory. I doubt it matters in practice in a home. It matters in a room full of servers where there are thousands of drives vibrating, I guess.
Still, for a work machine, the extra reliability may be worth $60 more. You decide. Mind you, the WD1001FALS is very reliable already, and you should back up your work often anyway.
There are also the Green drives, like WD15EADS, but those are ideal IMO only for rarely accessed files or for storing movies. That is, they are slower and would reduce your productivity if you use them for frequently modified data files.
The WD640 GB Black is the same drive as the WD1001FALS, but with 2 platters instead of 3. Same performance, reliability, etc. A bit more expensive per GB. I used to recommend the 640GB a lot, but these days the sweet spot is the 1TB drive.