Just a PowerEdge 2850, dual Xeon 3.6, 8 GB RAM, running ESXi. That's roughly equivalent to the box it's replacing, the bulk of its duties is building snapshots. Box is working well, I just need to get the blasted DRAC reset to factory defaults (always a pain…) and we'll have it down to the datacenter this weekend.
The one we use for builds where very fast builds are more important is a dual socket quad core Xeon, also with ESXi.