I didn't upgrade for ARR, as my old computer handled 1.0. I did, however, upgrade to this recently-

Cheapo MSI Z77
I5 3570k (can do 4.2 on air, but have no reason to so its back to stock.)
8gb DDR3 1600
HIS 2gb HD 7850 @ 1ghz. Need some new games, can't even make it break at sweat @ 1080p.
120gb SSD for OS, ARR and a few other things.
WINDOWS 7. I hate 8 so much.

Radacci- Get the SSD. It'll be the best upgrade you have ever made to a computer.