hey im planning to build a gaming pc for my brother so me and him could play starcraft 2 together for over a monght doing reserche on what to get and a have 3 choice i waunt the best pc to runs starcraft at 1080p at ultra setting i have tree differrent configuration
the fist one the apu
CPU-> a10-5800k
GPU->hd readeon 7850
RAM->8G speed 1866
MOBO->ASRock FM2A75M-DGS
Price->$554.28
the second configuration is the phenom 965be
CPU->phenom 965be
GPU->hd readeon 7850
RAM->8G speed 1866
MOBO->ASUS M5A97 R2.0
Price->$541.88
last choice is the intel i3 2120
CPU-> i3 2120
GPU->hd readeon 7850
RAM->8G speed 1866
MOBO->MSI Z77A-G41
Price->$572.36
all the pc has to be able to do is run starcaft 2 at max setting whish one would be the better option in price for performance http://www.anandtech.com/bench/CPU/129
I would have gone with the second alternative, If the motherboard is am3+ capable then you should have no problem getting a newer one later, Even steamroller is going to be in the am3+ socket so you should go for the second alternative imo
For every other game i would go for the 965 but starcraft is very cpu intensive so it would be worth spending the extra on the i3 2120 and you still have the upgrade path to a i5 3570.
That rig should be able to do ~50 fps with every thing maxed out if you are wanting to mess around and have fun thats pleanty and it will look great.
If you want to play competitively then you will probably want to set everything to its lowest for best fps and to make the game look cleaner. You might also consider a cheap ssd as when you get into a game on a map you havent loaded before there is a slight delay of maby 0.5 seconds and some frame dropping giving the oponent a head start an ssd will help prevent that. And get a good gaming mouse you really do need somthing with high speed and precision.