Econobox alternatives
We're happy with our primary selections, but not everybody will want an Intel processor or discrete graphics. Since users' needs will invariably, er, vary, we've gathered a list of alternatives and extras below.

Processor
Athlon X2s may not be particularly interesting alternatives to Intel's cheap duallies, but the Phenom II X3 720 Black Edition isn't that expensive a step up, either—and it's an altogether different class of product capable of much stronger performance. Heck, we'd even pick the 720 over Intel's $165 Core 2 Duo E8400 for general desktop use. The Phenom offers a similar level of performance in many single-threaded apps, but it can zoom past the E8400 in multi-threaded tasks thanks to its extra core. Also, the Phenom's unlocked multiplier makes it easier to overclock.

Motherboard
We have a budget to think about, so we're recommending a motherboard with integrated graphics to complement the triple-core Phenom. We view this combo as an alternative to the Pentium, P45, and discrete graphics trifecta. That trifecta better suits shoppers who care about gaming and GPU performance. If you don't need particularly powerful graphics, we think you'll be better off spending the same amount of cash on a system with a CPU that has more and faster cores.

The main job of our chosen Gigabyte GA-MA780G-UD3H is to accommodate the Phenom II X3 720. However, this board also happens to feature AMD's very capable Radeon HD 3200 integrated graphics processor, which can still handle casual games and high-definition video playback. That's about all the graphics horsepower many folks will need from a $500 PC.

Graphics
Naturally, some readers may want more GPU power than what our default configuration offers—not less. XFX's GeForce GTS 250 1GB should serve those users well, because its 1GB of memory and high clock speeds enable it to produce smooth frame rates at higher resolutions (and with more eye candy) than the Radeon HD 4850. Variants of the 4850 with a gig of RAM do exist, mind you, but they're not quite as fast or as cheap. This XFX card has a double lifetime warranty and a free copy of Call of Duty: World at War thrown in, so there's little not to like.