For just the cpu prob a 3570k as the hasewell cpus run quite hot when overclocked, or else a fx 8350 both cpus overclock quite far, intel usually around 4.6ghz, and some with the 8350 get lucky and can reach 5.0ghz. Both get similar performance, where the fx wins in multitasking performance and rendering. The i5 is prob the best for gaming even though its a quad core, it still competes against the fx in rendering and most multitasking so unless ur a hardcore amd fan or want 8 cores the i5 is prob ur best choice.
If ur going to rendering and editing quite often then prob spend an extra $30 if ur cpu budget is $300 and get the i7 3770k
These answers are outdated. If you're looking for an Intel processor, the i5 4670k will be the latest gaming CPU you'll be looking for. The 2570k was the favorite CPU from the Ivy bridge generation but since June, the Haswell processors have been available. In general, you can expect a 10% performance boost over Ivy Bridge. You can read up more about Haswell here.