You should get
http://www.jimmspc.fi/tuote/R-VGA150900F%2B as it runs every game that has been made so far. I have myself HD 3450 and it runs even Crysis but with low graphs

Still waiting for new processor and when it comes I'll have:
ASRock ALiveXFire-eSATA2
HD 3450 in CrossFire
AMD Athlon 64 X2 6000+ 3,0 GHz or AMD Phenom II 920
3072 Mb 333 MHz
570 Gb
Ace Raw Deal 620W PSU
And that should be enough to run every game, even GTA IV or Crysis.
Now I have:
Motherboard: Fujitsu Siemens MS-7293VP
Processor: Intel Core 2 Duo E4300 @ 1,8 GHz
Video Card: ATI Radeon HD 3450 512 Mb
PSU: Ace Raw Deal 620W
RAM: 2x Samsung 512Mb 266 MHz
HDD: Samsung 250 Gb & 320 Gb