Kestrel_909,
If you were to build a gaming machine this is what I would recommend:
ASUS A7N2X-E Deluxe or MSI K7N2 Delta-ILSR
AthlonXP 2500+ Barton Retail with Heatsink/Fan
2 x 256Mb Mushkin High Performance Level II Black CAS2.2.2 PC-3200
ATI All in Wonder 9600Pro or MSI GeForceFX 5700 Ultra
2 x Western D Raptor 10,000 SATA Hard Drives w/8MB Cache, Raid 0 (16k Stripe)
Lite-On DVD+/-RW
Antec SLK3700AMB or Antec Sonata Case
Logitech Z-680 500W Dolby Digital DTS THX 5.1 Speakers
WinXP Pro SP1
I think you should first look at upgrading your current system's RAM & Vid Card, but if you are ready for a new comp, the specs above would make a great gaming system that would not break the piggy bank.
Take Care,
Richard