Best upgrade(s) for $500 (for my system)

get a cheap sli mobo, a q660 or a e8400/8500, another 8800GTS and 2 more Gb of ram and you are good to go.

Q6600, 185 bucks
680i LT mobo, 100 bucks,
8800GTS 512, 150,
2 GB of ram, or a new 4 GB pack, 40 bucks

The total is....under 500 dollars and you have my current setup, which is running great, my q6600 is oc to 3.0 and i am going to try and go to 3.2 or something. I play far cry 2 and everything on very high with no aa and it runs great.

trust me Mrbumbum, sli, is not always the way to go, having used sli in the past i will tell u it yields a performance boost, but only in some games. As a recomendation since socket 775 is going out the dor save ur chips dont buy the quad core or the 680i mobo, i own both parts and they are great but not worth investing ur money in now. I say ur proc is VERY capable, if u REALLY need to oc then possibly buy the 680i but the quad is a waste now. Instead seel ur 8800gts and buy either a 4870 1gb or the gtx 260, extremely powerful(trust me i know i own a core216) and dont have worry bout sli support   As for ur memory if its rated for 800mhz and it wont run at that either ur board doesnt support it or if uve tightened the timings realx them, if neither of these are the issue then warrenty them

There a couple of ways to go here:
Option #1 (cheapest):

Upgrade mobo to p45 - $100-130
Comparison list of several good p45 based mobo's
Upgrade to 4 gb's (2x2 usually is better than 4x1gb's) - $25-60
CORSAIR 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
Upgrade CPU HSF - ~$30
ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler - Retail
OC your CPU to 3 gHz or more.
Total upgrade cost - ~$155-200

Option #2 (probably a good option):

All above +
Upgrade GPU to 4870 512mb/1gb depending on budget limit - $215-270
1gb 4870 GPU $270 after MIR!
Total upgrade cost - ~$370-470

Option #3 (Mostly CPU upgrade from above option, but quite thorough!):

Upgrade CPU/mobo (e8400/p45 Asus p5q pro combo) - ~$250
3rd combo up from the bottom!
Upgrade to 512mb 4870 - $215 (after MIR's)
ASUS EAH4870/HTDI/512M/A Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
Upgrade to 4 gb's of DDR2 (2x2 gb's so you can get dual channel) - $25
CORSAIR 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
Total upgrade cost after MIR's - $490!!!

well i can see ur an absolute ati fanboy and dude trust me the diff between 2 and 4gbs of ram is dick for gaming, dont waste ur money

Okay here's a conclusion on 4 gb's vs. 2 gb's of DDR2. It just one version of it, but it does help. You can decide if it's something you want for $25??
Quote:
Final Thoughts and Conclusions:

Inspired by the Corsair Performance Analysis of 4GB versus 2GB of memory we figured it would be fun to see for ourselves how gaming performance is impacted by adding more system memory. Corsair did a great job on memory usage and the difference between 32-bit and 64-bit operating systems, so instead of trying to re-invent the wheel, we suggest that you check out their report. The Corsair performance analysis only used three games so our goal was to use a wider selection of games and see how much, if at all, the average framerate improved. Our findings, based on nine game titles, have shown that 4GB of memory does offer framerate improvements over using 2GB of memory. The observed difference was so small it would be hard to notice while gaming. Synthetic testing was also a wash since 3DMark 2006 gained performance while 3DMark Vantage seemed to take a slight performance hit.

Our average framerate increase of 1.6% in nine games was slightly higher than the 1.1% shown by Corsair in the three games they tested, but our test system was a little newer and we were running Vista SP1. Something else that we noted while running the benchmarks is that game loading times were also significantly enhanced by installing 4GB of system memory. While that was not the focus of this article (framerates was) we noted that Crysis v1.21 loaded 54.1% faster (14.28s versus 22.00s) on the initial level load. After the level was loaded and then restarted (as if one died and started over) the load times were within a hundredth of a second. Obviously, having more memory will also help other areas and at the end of the day it helps performance. If you're going to be building a new gaming PC then by all means use 4GB as it does help performance, but don't expect a night and day difference in the gaming benchmarks.

Legit Bottom Line: The Corsair PC2-9136C5 4GB memory kit is one super fast memory kit and helps improve performance over 2GB memory kits on the majority of the 11 applications we benchmarked it on.

Link to review.
Another review link. Look at the differences with Dx10. Peak isn't too much different, but minimum is quite a bit different.

IDK, but it's up to you, I'm just suggesting the extra 2 gb's for all around system performance. For $25 it's hard to overlook.

And to answer your ATI fanboy statement: I'm not an ATI Fanboy. I currently have several computers 2 with ATI GPU's and 2 with nVidia GPU's, so don't label me as an ATI fanboy. I only recommend what is the best for the $. If you go back to my numerous posts in the last couple of years, I've been suggesting nVidia more than ATI (AMD) for GPU's, because until the 4xxx series came out, nVidia had the better GPU's out on the market.

those fu*kin 11 apps that the system made better us of the 4gb over 2gb are nont gaming, jesus christ pll!!!

load times may be quicker initially but if he's not using vista*cough******cough* it doesnt enhance his performance

That is why he states "Vista Home Premium 64 bit"

well still he only has 500 to spend, dont waste it on mem, get faster gaming performance with a better gfx card, just money spent more wisely