I'm still using an ancient I7 980 which still eats everything alive, even at stock speed.
Later generation I7s are still totally overkill, you cant go wrong with them.
I remember AMD needed to clock their latest CPU to 5 Ghz, and its still not on par with Intel's I5's / I7's, and consumes a huge amount of power and runs really hot. Plus most I5s / I7s can be overclocked to 4.5 Ghz+ if you ever want to and then they just just laugh at every feeble program / game that you run.