ok why dont you guys just tell him which cards will play those games nice? who cares if his system is going to bottleneck thats not what he asked us. the only question that was worth asking was agp or pci-e who cares about favourites he asked what card would be good. anyway!!!!!
ok the 6600gt will play doom3 very nicely on high settings, it plays CSS very nicely, it plays hl2 very nicely, it plays anything very nicely. requires a 350w psu though. from ATI i wouldnt go below the x800. 6600gt's come in pci-ex and agp. and the x800 im pretty sure comes in both.