At US $330, I would personally buy an overclocked GTX 660 TI. However, most people would direct you to an AMD 7950. The 7950 is probably similar--if not a little better--performance, but some people report driver issues depending on your hardware. You might not have any though.
But like Sunius said, you might really be looking at US $250 cards because of higher prices in Europe. Check out his links for GTX 660.