Backing up your photos and music is vitally important. Even though I use optical media too, the ease of backing up to redundant hard drives has made this my favorite and most-used option. And as we all know, the easier it is, the more often we'll do it.
My current favorite drive is the LaCie 300GB d2 External Hard Drive With Triple Interface ($225). It combines 3 interfaces (FireWire 400, FireWire 800, and USB 2.0), fast spin speed (7200 RPM), decent buffer (8MBs), excellent reliability, and good looking design. I've been using d2 drives for years now (have five in two locations), and I've been very satisfied with their performance.
These drives work equally well with both Macs and PCs. If you have a newer Mac, I recommend using the FireWire 800 connection for maximum throughput. By doing so, you also have your other ports (FireWire 400 and USB) for connecting other drives (such as an iPod) for copying from one device to another. LaCie provides you with the necessary cables.
Even though styling shouldn't necessarily be at the top of the list when considering a new hard drive, I have to say, I really like the look and feel of these units. The attractive metal case with cobalt blue light looks great on your desk, shelf, or wherever your store your drives.
You can daisy-chain these devices too so that they are all accessible at once. This makes it easy to search across all the units or copy data from one to the other. LaCie even makes a handy desk rack ($49) if your want to stack up to four units horizontally.
Indeed, there are plenty of hard drive options out there. And the most important consideration is that you pick one of them and start backing up today. But if you'd like an attractive combination of style and performance, include the 300GB LaCie d2 on your list of options.