What Amd/Ati Processors and Video Cards are best for Gaming?

What brand of AMD/ATI cards (raedon, etc) and processors (Turion, Athlon, Phenom, Dual-Core, Quad Core) will run games heavy in 3d like GTA IV with the minimum display settings set in the game. A little lag or two won't bug me but I want the game to run smoothly enough that it will be playable with whatever card and/or processor meets the minimum requirements. Yes I am looking at getting a Desktop.|||it depends on how much you are willing to spend. you could build a computer for 600 dollars that would play gta 4 at full max settings without a single hiccup. the Phenom II series are the gaming series processors followed by the Athlon II series. The video cards are rated in an order such as this. ati/amd radeon hd 2xxx 3xxx 4xxx 5xxx 6xxx. the higher the shown number is the newer the model is. the higher the xxx numbers are the higher end the graphics card is. the ati radeon hd 5870 for instance would be an extremely high end 5xxx series card and is pretty similar on performance to the radeon hd 6870 but the radeon 6870 has some newer features such as integrated 3d blue ray deciphering.