@ Adam202: At this moment in time ATI has the better cards in your price bracket. Do n't get me wrong, there's no problem with an Nvidia card but ATI cards give more performance per (place your currency here) than Nvidia.
For a two year ownership and given your resolution and CPU and if DX11 is a concern the HD5750 is the best fit. If you are not bothered with DX11 then look to the HD4870, it's a fair bit faster than the 5750 and can be found for about the same price.