well the GTS 250 and HD4850 are not within your budget so settle for the GT 240. if your screen resolution is <= 1280*1024 then you can very well play the games including crysis and metro 2033 at medium-high settings. Go for the ddr5 version of 240 as the ddr3 version is no good... HD5570 ddr3 better than GT240 ddr3
^ Lol mal that's only cause you like Nvidia more. I personally think both choices are great. The 5670 being the better buy because it has DX11 support, not because it has DDR5 vs DDR3. But DX11 support is most likely going to be the future DX for games. So you'll be future-proofed in a sense.