I built mine a little over a year ago have made only a few changes on it.
Current specs are:
AMD 6400+ X2 CPU
ASUS M2N-SLi Deluxe MB
Silverstone 600watt PSU
Seagate 320gig HDD
2gigs Corsair XMS DDR2 800
ATI 1950XT 256mb VPU
lotta' fans and a huge case
and a 22" widescreen and 17" standard monitors