I want to install a video card?

i wanna buy a laptop and i wanna buy the best and latest video card for that i should have all sort of latest functions like best graphics, 3D effects, and many more. Please tell me that which is the best video card?|||correct me if I am wrong, but you cannot buy Desktop PC cards and try to fit them into laptops.|||get at least an nvidia 7600 go graphics ... better to get 7900+ ifu can afford it ...|||letest nvidia?|||Ati or Nvidia 256mb or higher