For the long run, Intel CPUs holds up very well.
An i7-920 purchased in 2008 on average is very close to an FX-8350 purchased in 2012 in terms of game performance.
I would avoid the AMD A10-7850k APU altogether. There while AMD has made some improvements versus the now older Richland APU, the fact that clockspeeds have been lowered offset much of the performance improvements AMD has done. Of course you can overclock it, but they will be less power than AMD's FX Piledriver CPUs which are in turn less powerful than Intel's Core series CPUs.