$600 - $800 budget

I was wondering if someone could give me a little assistance on build a new computer. I have around $600 -$800 to spend (would like to spend as little as possible, but not cut corners) to build this new computer. Anyone want to build me a computer? This computer would be used for gaming and surfing the web. Any help would be appreciated!!!

Do you have any spare parts or are we building this one from the ground up?

I'm building up from the ground minus the speakers and monitor still have those from my old computer. A couple other things to add. I was originally going to go with a AMD Athlon 64 x2 6400+ and motherboard combo, but my friend was telling me to go intel because they have better performance and less heating problems. So I'm kind of stuck with either going Intel or AMD. I figure the Geforce 9600 GT would be a decent card, but unsure if there is something out there better for the money. And I'm confused on which brands are better then others. They make like 10 different 9600 GT cards.