I've been setting up a home file server and HTPC with a MacMini and, in the process, I found myself shopping for hard drives. It's amazing how cheap they are (about $80-100 for 2TB these days) when you consider what they do (i.e., holding all of your precious digital memories).
Unfortunately, other than relying on your own good and bad experiences, making informed decisions about purchasing new hard drives is next to impossible. The most important factor in a drive is reliability, but there's no way to know if the drive you're shipped is going to fail in 6 hours, 6 months, or 6 years. Compounding this is the fact that almost all reviews -- particularly those from customers on retailer websites -- are anecdotal by nature. Read the 1-star reviews on Newegg or Amazon for any hard drive and you'll soon be looking for another model. And then another. And then... they all start looking equally awful.
Storage Review takes hard drive reviews seriously. In searching for some reliable, large, and quiet drives, I followed their recommendations. I particularly found their "Leaderboard" of best drives useful and, after a little cross-checking, followed their recommendations.
Mac Performance Guide, on the other hand, is home to a motherlode of tips on optimizing a system. The site, authored by photographer Lloyd Chambers, bills itself as "offer[ing] the web's clearest advice on selecting and configuring a Mac, especially for photographers." That's quite a claim, but I can't refute it. The Articles and Guides section -- which has multiple articles on backup, data safety, and optimizing Mac performance -- is outstanding.
By the way, I ended up purchasing three different drives: a Western Digital Caviar Green, a Seagate Barracuda Green, and a Samsung Spinpoint F4. I bought none of them in confidence, which, I suppose, is the way you should always buy a drive. That's why you have backups.