What is the cheapest core processor that is good for gaming?

I would like a core processor that is good at running games like Grand Theft Auto IV or Crysis on High.It could be a dual core, a triple core or a quad core.I would like the price to be around $100 – $250 or higher if necessary but I want the cheapest one available on the market. Thanks.

Athlon II X4 620, 2.6GHz quad-core for $100
Phenom II X4 955 Black Edition (great overclocking) 3.2GHz for $165 (recommended)
Intel i5 750, 2.66GHz quad-core, 2.66GHz for $200 (Intel recommendation)