Upgrading GeForce 8600GT to.....

Can anyone advise me on what graphics card to upgrade to, i am running a AMD 64 x2 Dual processor 5600 - 2.81GHz with 4GB of RAM, i have a budget of around £150 i want ot improve he graphics ready for the new call of duty... any ideas ?

Cheers Guys

 

whit that budget, absolutely gtx460

 

whats the difference between the Zotac, Gainward, Palit, PNY ?? are these different producers ???

 

also will i need to upgrade my power supply ???

 

Take cheapest, I live finland, so I don't know yours models there, different manufacturers have own cooling systems and maybe oc models, but cheapest is enough to you

what you have? good 400w be enough, hopefully u understand my school english

 

its on order - now roll on 11-11-10 for COD Black Ops