I'll rephrase.
i5 is way better for gaming.
FX (stock clocks) can be better for some very specific workloads but modern games are multi threaded.
Also, the i5 760 can be overclocked to 4.xGHz within reasonable voltage.
Anyway the gaming performance difference between lynfield i5 (like i5-760) and skylake (like i5-6600K) on the same clock is about 10-15%.