BF2S Forums Vid card suggestions

I'm looking to get a new vid card because by Nvidia 8300 GS is not doing the trick. I'm looking to get another Nvidia, but, I'm not really tech smart when it comes to vid cards (or PC parts in general). So, I'm wondering what would i need to get for a vid card to run current, demanding games at at least med settings at 1680 by 1050 resolution? But, i would really like to run CoD4 at high settings (right now my vid card can handle low settings across the bord with the default resolution). I'm willing to spend around $150 or so, but, i have a feeling that's not going to be egunth, so, maby two suggestions, one within my price range, and one that will do what i want? Thx in advance for any suggestions, also, the rest of the PC specs are: Vista 32, 3 GB Ram, Intel Core 2 Quad CPU  Q6600 @ 2.40GHz. And, if it matters, Vista rating 3.3 vid card is holding it back, everything non graphic related is in the 5s.