evga 760 2g or zotac 760 4g?

Usually, You only buy cards with more Memory if you plan on SLI'ing in the future. Though, If they are the same Price, I would get the 4GB Version.

Extra Frame buffer would be useful if you play higher than 1080, Run alot of high resolution Texture Mods, Or If you dont plan on upgrading for a while, Let you keep higher texture settings in future games. And of course SLI
 
i'll only be playing 1080p and probably not SLI anytime soon, both come with assassin's creed, and the evga seems to have more positive reviews. i just didn't know if i'd actually NEED a 4gb card.