Er a lot!
The only thing I recommend is getting i7 Core over a i5 Core if possible.
Pretty good memory, 1600MHz DDR3 is fast.
Good Hard Drive, spindle speed of 7200RPM is standard, but 32MB cache is awesome.
Good Power Supply, wouldn't need too much more unless your SLI multiple graphic cards.
NVIDIA GeForce GTX 460 768MB GDDR5 Graphics Card, is a great card for gaming.