Gaming Upgrade Build $300-500

[Rendition]

1) What will you be doing with this PC? Gaming? Photoshop? Web browsing?
-Pure gaming

2) What's your budget? Are tax and shipping included?
-$300 to $500 ex-tax and shipping. I want best bang for buck though, cheaper the better.
-NewEgg is preferred vendor

3) Where do you live?
-East Coast USA

4) What exact parts do you need for that budget? CPU, RAM, case, etc. Please be very specific.
-Would like a new CPU, RAM, Motherboard, Videocard, CPU Fan/Heatsink combo

-I currently have a Core2Duo 2.1ghz E6400, 2GB DDR2 800mhz, Gigabyte GA-965P-DS3, Nvidia 8800GT, Intel retail CPU fan

5) If reusing any parts, what parts will you be reusing? Please be especially specific about the power supply. List make and model.
-Power Supply: SeaSonic S12-500 500W ATX12V
-DVD/RW Samsung
-Case: Antec Solo
-Monitor: HP 24" LP2475w
-HD: Western Digital 120gig

6) Will you be overclocking?
-Sure

7) What size monitor do you have and/or plan to have?
-HP 24" LP2475w 1920x1200

8) When do you plan on building/buying the PC?
-ASAP. Willing to wait 1-2 months, if something great coming though

9) What features do you need in a motherboard? RAID? Firewire? Crossfire or SLI support? etc.
-None

10) Do you already have a legit and reusable/transferable OS key/license?
-Yes. Windows Home Premium

I basically want the best value/performance upgrade of CPU/RAM/videocard/motherboard/CPU fan to play games at 1920x1200. I would like to play Crysis Warhead at reasonable frame-rates (30fps) at high graphic settings at 1280x960. I'm also looking forward to playing Modern Warfare 2 later this year.

Some combos I've considered are overclocking Intel E5200 (what CPU fan? motherboard? RAM for good overclocking?) with Nvidia 260 216 core videocard. Is this the cheapest value/performance? How high can I overclock E5200 with a specific cooling CPU fan, motherboard and RAM?

Another combo I'm considering is over clocked Phenom X3 720 (which CPU fan? motherboard? RAM for good overclocking?) with Nvidia 260 216 core videocard. How fast can I overclock with a specific CPU fan/ram/motherboard? Is this best bang for buck?

I am also worried about the 500 watt power supply, if that would be enough to handle various combinations over-clocked.

Thanks for the help in advance.

 

[Rendition]

I also play real-time strategy games. I plan to play Starcraft 2 and pick up Total War.

 

[robotlegs]

CPU + Mobo: $270 AMD Phenom II X4 940 + Gigabyte GA-MA790X-UD4P mobo
HSF: $42
RAM: $50 (+ $10 MIR) OCZ Reaper HPC 4GB DDR2 1066
VID: $170 (+ $20 MIR)

Total: $532 shipped. ($502 after MIR)

I know its a little more than you want to spend. But its a good price/performance ratio. If you're not overclocking you can probably drop the HSF to save $42. And if you want to drop the video card price a bit, you can get a ATI 4850 for ~$120. If you want to drop CPU price, look at this combo (http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.190734 $219)

That would put you well below $500.

Not sure if your PSU is good enough though. Someone else might be able to assist with that

 

[Rendition]

Thanks! Can someone put together a Intel E5200 overclock build with CPU fan/ram/motherboard for comparison?

 

[engiNURD]

Simply switch the CPU to E5200 ($70) and board to GA-EP43-UD3L ($80).