Gaming PC >$750

Approximate Purchase Date: March 2011.

Budget Range: 600-750 after rebates. EDIT: Crap, I put > instead of <. Sorry, guys.

System Usage from Most to Least Important: Gaming, internet surfing, movie watching.

Parts Not Required: I need everything except a sound card, because I don't think the money would be worth the gained performance.

Preferred Website(s) for Parts: I would prefer newegg, because I trust them, but whatever site would offer me the best prices/shipping/taxes.

Country of Origin: U.S.A.

Parts Preferences: I don't really have a preference, honestly, because I've never gamed on a PC to a point where I would rather one or the other. I am looking for performance-based suggestions, not biased ones. I do know that I want a quad core CPU, though.

Overclocking: Yes

SLI or Crossfire: No

Monitor Resolution: I don't know about this one, but I would rather the highest I can get for the price.

Additional Comments: I'm kind of a noob when it comes to hardware, so I'm looking to learn from this. Also, I'm confused about all of the brands, because from one guy I hear Intel's the best and AMD sucks, and from another I hear different. Is there really any performance gain of an i5 over a Phenom II X4 running at the same speeds? And thank you for your input, in advance.