Throughout the year I will be watching the prices of hard drives, particularly 2 terabyte drives for my home computer. I currently have a pair of Samsung 1 TB SATA drives in a RAID 1 array. I am using the the RAID controller built into my ASUS M2N-E motherboard, but may look into a better controller.
Currently 2 terabyte drives are about $350 Canadian. I paid just about $100 each for my 1 TB drives late last year. We'll see how long it takes for the 2 TB drive to get down to $100. Hopefully by early 2010. 1.5 TB drives are currently about $150 and seem to be steady for the moment.
I'm pretty paranoid about losing my data, so in addition to the RAID array, I have another large internal drive, as well as an external drive for backup.
Next time I have to rebuild my system, I'll make a Ghost image of the basic drive (less programs and data) and store it on DVD or portable drive. I use Symantec Ghost Suite 2 at work and it seems to work great with network or local backups.
Getting back to hard drives, the worst part is that these new drives seem to generate a ton of heat. I bought a pair of Noctua 120mm case fans to keep my system cool. This is in addition to the power supply fan, the CPU heat sink fan and the graphics card fan. The Noctua fans at $20 each weren't cheap, but were some of the best around. All of my fans were purchased with noise level in mind. Maybe one day when I have more time and money, I'll try to build a really quiet computer.