i agree with mark, try to find a nVidia card!!
i've got a geforce 5700LE myself.
i can play games like ut2k4 with al the details set to high and with a high resolution ( 1280&1024 ) very good ( around 30 to 40 frames per second )
if i set it to 1600*1200 i can sense some framedrop ( around 10 to 25 frames per second )
I think my video card is good enough to play the newest games ( didn't play doom3 yet, but im almost sure my computer can handle it

)!!
i've got the geforce 5700LE for 150 euro ( not sure how much dollar that is )!!
but mark's card is just a bit better i think!! didn't see that card in action though!! its price is around 200 euro ( again, not sure how much dollar that is

).