1) Rig type?
Desktop running Windows XP Pro SP3
PSU = Enermax MODU82+ 625W
Mainboard = MSI P4N Diamond
2) Processor?
Pentium 4 660 @ 3.6 GHz, 2 MB L2 Cache, 800 MHz FSB
3) Graphics card?
MSI 9800 GTX+, 512 MB GDDR3, factory overclocked to 760 MHz core, 1880 MHz shader, 2300 MHz memory
4) RAM? Hard drive?
RAM = 2 x 1GB Crucial DDR2 PC5300 @5-5-5-15 timings
HDD = 2 x 74GB WD Raptor SATA1.5 in RAID 0 for OS and game installs
1 x 160GB WD Caviar SATA3 for data storage
Monitor = Samsung SyncMaster 245BW, 16:10 aspect, native resolution 1920x1200
5) Benchmarks?
Never benchmarked. I do most of my gaming at monitor's native resolution and if the game gets too laggy then I'll turn down quality levels instead of resolution. Someone mentioned the burning and battling Vizima level of The Witcher though and I do recall my rig getting herky-jerky in that portion of the game.

It runs Mass Effect fairly well at native rez and high detail settings.
When I built this rig back in late 2005 it was pretty good. The only thing I upgraded since originally build were the PSU and video card. But it's getting kind of long in the tooth now and I plan on replacing all components except for the video card next month.