Budget System Under 500 with good potential to overclock and tweak.
Intel Pentium G3258 is a low-priced, multiplier-unlocked, Haswell-based processor that will give the i3 and FX-6300 a run for its money. Few choices on video card but I went with GTX 750ti over the Radeon R7 260X for a few dollars more I it has a lower overall wattage requirement to allow more headroom for upgrades.
Like most builds budget builds out there I will not include Optical drive, I plan to run steamOS where you download all your games.
I will be over clocking with the stock cooler, if I run into problems I can upgrade since currently 125 dollars under budget after rebates. There is also room for mouse,keyboard and monitor & windows7/8 if you shop around for deals.
$10.00 mail-in rebate