Processor:
Intel Core i7-2600k 1155 3.4Ghz Quad Core $314.99us Overclocked @ 4.8Ghz or
Intel Core i7-990x 1366 3.46Ghz Six Core $999.99us Overclocked @ 4.7Ghz

Motherboard:
Gigabyte GA-Z68X-UD7-B3 1155 $349.99us or
Gigabyte G1.Guerrilla LGA 1366 $299.99us

Cooling:
Liquid Cooling System (Ultimate Performance) Cpu, Chipset & Video Card

Memory:
Corsair Vengeance CMZ8GX3M2A1600C9 8Gb 1600Mhz CL9 (2x4Gb) for 1155 $84.99us or
Corsair Vengeance CMZ12GX3M3A1600C9 12Gb 1600Mhz CL9 (3x4Gb) for 1366 $131.99us

Video Card:
EVGA Geforce GTX 580 FTW Hydro Copper 2 $699.99us

Power Supply:
750w/775w/850w/875w

This is just a base to get you started... I call it a Mid Level Gaming Rig...