ThanosB :
Hey I have an nvidia gt210 1gb ddr3 gpu and I can paly AC:Brotherhood in low settings (maybe with some settings in medium) at this resolution. I even palyed AC 3 with low settings at 800x600 resolution very good. In some games like nba 2k13 or PES 2013 I played at 1280x1024 with the settings at medium-high. I believe that any gpu better than that could play games at 1024x768 with good enough quality.
well ThanosB. i have xfx radeon hd 5450 and it is better than the gt210 ,but it's a realy bad performer,even at 640x480 resolution with low settings.( CPU: intel pentium dual core e2220. RAM: 6gigs of 1333mhz RAM).