I just read an article on digg about how the new generation Nvidia cards are causing all kinds of BSODs. I would wait a bit until a fixed driver is released or for the ATI to come out.
the bfg 8800gts oc cards are the best deal for the price as far as the new 8800gts 320mb cards go. the non-oc ones for the same price are obviously not as good.
the 7950gt is not great for the money. for 250 you can get the radeon x950xt and it's an amazingly better card than the 7950gt, but runs hot as hell.
the 7900gs is pretty much the only geforce worth the price right now unless you want to get one of the aforementioned dx10 cards.