AMD 5770 1gb should curb stomp that gt 220.
Unfortunately right now I can't recommend a single nV card as they are all ludicrously overpriced.
Here I can get a 4870 1GB for the same price as a GTS 250 1gb or for way less than the GTX 260 Core 216 that it actually competes with.
4870 1GB if you can get a good deal on one and have the PSU to run it or 5770 1GB which has similar performance to the 4870 but offers more features and draws less power and is DX11
Link for comparisons