Graphics Card Advice?

hey, im looking into getting a new graphics card for my pc so i can play the new call of duty modern warfare 2. i need 256 MB NVIDIA GeForce 6600 GT or better or ATI Radeon 1600 XT or better which i have found for some pretty cheap prices, around �40 and above, but is this good? i mean for that price you cant be gettin much can you. Also whats a good graphics card for a cheap price, im willing to play up to around �70-�80, but if theres something cheap and good ill look into that.