A (file or personnal) server. Does NOT have Windows. I had Linux on it and planned to use it as a server; but never did. I ended up using my regular desktop for the same purpose. The system had been up for only a few days.
Specs: AMD Athlon X2 dual-core 3.0GHz, 4GB of RAM and 1.0 TB SATA disk, etc.
Price: $199