I recently speced up a cheapish PC for a friend with scan.co.uk parts. I wouldn't go lower spec than this for a games machine.
It goes a little something like this..
Specs 2.4Ghz x 2 (Dual Core), 2Gb Dual Channel RAM, 250Gb Hard Drive, CD/DVD Recorder, add a 19" LCD monitor depending on budget.
the parts codes..
LN21083 Intel Pentium Dual-Core, E2220, Socket 775, Allendale Core,
2x2.4 GHz, 1MB Cache, Retail £45.49 £53.45
LN21758 Gigabyte GA-945GCM-S2L, i945GC, S775, PCI-E (x16), DDR2
400/533/667 MHz, SATA II, µATX, On Board VGA £27.32 £32.10
LN12200 2GB (2x1GB) Corsair TwinX XMS2, DDR2 PC2-5400 (667),
240 Pin, Non-ECC Unbuffered, CAS 4-4-4-12 £23.54 £27.66
LN16941 250 GB Maxtor STM3250310AS DiamondMax 21, SATA II,
7200 rpm, 8MB Cache, 11 ms £29.10 £34.19
LN8232 Scan '2012' 4 in 1 Kit. Black/Silver inc Keyb/Mouse/Speakers
ATX Midi Tower 400W Passive PFC PSU £23.60 £27.73
LN20986 Optiarc AD-7191S-0B 20x DVD±R, 8x DVD±DL, DVD + RW x8/-RW x6,
x12 DVD-RAM SATA Lightscribe Black oem £14.71 £17.28
LN21476 512MB Palit 8600GT, PCI-E (x16), GDDR2, 2xDual Link DVI-I/HDTV £41.42 £48.67
TOTAL 1 = £241.08 no monitor
LN21876
19" Hanns-G HW191DP Silver/Black Widescreen LCD, 1440x900, 700:1, 300 cd/m², 5 ms, Speakers, VESA £84.49 £99.28
Add a monitor TOTAL 2 = with new slim 19" LCD monitor add £100 = £341
If you think you may want Windows Vista it's best to buy it with the
parts because it's cheaper as Vista 32bit Premium OEM add £57.
DinoHunter (still no nVidia compo voucher!), CPU/GPU Benchmark, DarkFish Encryption DLL, War MMOG (WIP), 3D Model Viewer