As the smallest members of the desktop computer family, compact PCs often omit features to deliver computing power in a tiny package. The combination of energy-efficient components, quiet operation, and small size makes compact PCs ideal for people who want a nonintrusive machine. A typical compact PC costs between $300 and $600, though the price rises as you add optional upgrades.

Compact PCs tend to be equipped with laptop or netbook components, such as Intel Atom processors. That limits their usefulness for tasks that demand lots of processing power, but it makes for quiet, energy-efficient operation. Not all compact PCs are created equal, however, so pay attention to specifications when shopping. Some compact PCs are configured for as low a bottom-line price as possible; others are packed to the gills to provide optimal performance in a tight space.

When you're checking out a compact PC, keep an eye on the number of available ports, and think about what you'd like to use. The smaller the system's footprint, the fewer features you can reasonably expect--and that includes fewer connectivity options. HDMI ports have become increasingly common, and are an asset for home theater setups. The typical hard-drive size is 320GB, though 250GB is also common; we've seen some compact systems carrying up to 1TB (for a $100 upgrade premium). For a chart of recent high-ranking PCs in this category, see "."