As current and future video games start reaching the 2GB limit for VRAM, it depends if you want to future proof your card. BigMack70 is correct in that you may want to get if you get a multi-monitor setups. But, also very high or ultra graphic settings such as anti-aliasing, ambient occlusion, and other filter settings. This also means for any resolutions higher than 1920x1080.
So, for that a resolution of 1360 x 768, the 2GB card will be more than enough for any games you play.