Well, the Haswell Refresh CPUs that were just released (i5-4690K and i7-4790k) should give great results, but I haven't seen anyone with it yet do any actual testing since they're too new.
But since I think you're referring to your laptop, you must ask yourself if you're hitting any speed issues with the games you're playing. Test them out on your current CPU, and if you think that it's worth it, then yes, spend about $200 or so to get the i7-4900MQ (that's the fastest one that I know of off the top of my head)
edit: its actually the i7-4910MQ, and is closer to $570 new still. With that money, you could build a 5th gen i3 based desktop that would be way stronger than the i7-4900MQ
But since I think you're referring to your laptop, you must ask yourself if you're hitting any speed issues with the games you're playing. Test them out on your current CPU, and if you think that it's worth it, then yes, spend about $200 or so to get the i7-4900MQ (that's the fastest one that I know of off the top of my head)
edit: its actually the i7-4910MQ, and is closer to $570 new still. With that money, you could build a 5th gen i3 based desktop that would be way stronger than the i7-4900MQ