Piledriver which is the update to the FX line up of cpu's is out in the next week or so and if i were you i would wait for that.It will have better performance and use less electricity.
I own an FX4100 and have it overclocked to FX4170 speeds and it runs everything i need it to including crysis 2 at ultra but if i were buying now i would wait just to see what piledriver is like. Any questions just ask and i'll be happy to help.