Motherboard:
MOBO: Intel P45 based motherboard. I particularly like Gigabyte boards - get one with DDR2, not DDR3 support - DDR3 is still too expensive.
RAM: Buy DDR2, 1066
MHz (@ 1.8v) for overlclocking headroom, set the motherboard for the lowest memory timing and then overclock the heck out of the FSB.
CPU: Intel E7200 is a good dual core, overclock friendly value CPU
Video Card: ATI Raedon 4850 (better) or 4830 (cheaper)
All that if you cant afford a core i7 & X58 - way better, way pricier.
