For my own future reference, here are the specs of the recently ordered computer:
Case
Cooler Master Centurion 5: I like how it looks, although I do worry about the possibility of having to clean a lot of cat hair out of the foam… I like that the internal bits can be swapped around without needing tools. The one I ordered supposedly has a window, which is nice. I swapped out the under-powered 350w PSU that comes with it, per Velius’ (and other peoples’) suggestion. The new PSU is a 550w Legolas Logisys. I hear the cheap ones can fail just as easily as the really expensive ones, so I went cheap.
Motherboard
Biostar I945GZ-M775 mATX with Intel 945GZ chipset and 8-channel audio: Pretty much the cheapest motherboard that would give me a PCI-e 16 slot and hook up to an Intel Core 2 Duo processor. Only supports 2×1GB of DDR2-533 RAM, but I’ll probably need a new computer by the time I need more than 2GB RAM.
CPU
Intel E6300 Core 2 Duo 1.86GHz processor: I really didn’t want to get a Pentium D, and I am a little shy of AMD this time. I like what I’ve read about the Core 2 Duo line, so I got the cheapest one…
Hard Drive
Seagate Barracuda 7200.10 SATA 250GB: Nothing too special, although it’s amazing how cheap space is these days. I more than tripled the amount the HD could hold for $30.
Memory
Corsair Value Select DDR2-533: I got two 1GB sticks of the stuff, and I’ve read that it’s a reasonable bargain without too much performance loss.
Graphics
nVidia GeForce 7100GS 256MB: Not really very good; supposedly the 7100GS is just a reworking of the GeForce 6200. Oh well, what’s the point of paying much for a DirectX-9 card anyway?
Audio
Random onboard 6-channel audio: I never splurge for a sound card.
Optical Drive
Random CD/DVD thing: I already have two reasonably new CD/DVD Read/Write drives.
I didn’t bother getting a monitor, keyboard, mouse, or OS because I already have all those things. I’m going to wait on Vista, as per Catnip’s suggestion; perhaps the Vista purchase will accompany the purchase of a new DirectX-10 GFX card in the future. Other than that, I totally cheaped out because I’m finding more and more than computers are becoming disposable after only a few years.