Mobo: asrock z77 pro 4
CPU: i5 3570k
GPU: xfx Radeon 7850
Ram: 16g
SSD: 120G samsung 480 series
HD: 2TB WD (one red one green)
OS: win7 (hate win8)
PSU: 600W
as for your friend here something for him/her
CPU Intel Core i3-3220:
$119
Ram Corsair Vengeance 8 GB:
$73
MOBO MSI B75MA-P45:
$68
EVGA GTX 650 Ti Graphics Card:
$145
WD Blue 1TB:
$70
case NZXT Source 210 ELITE Midtower:
$44
Corsair Builder Series CX 430w:
$41
-----------Total------------
$560
all of this will let him run modern day game from mid-high settings. While if he want more graphical power, tell him to get a better graphic card.
while the rest of the money tell him/her to use that for computer peripherals.
one suggestion to look into is mechanical keyboard.