So my current system is this:

AMD 64 XF 3000+ 2000mhz single core
   **stock cooler**
Chaintech SK8T800 MB
2GB micro center brad RAM
Western Dig. 300gb SATA 300mb/s HD **slowed to 150 due to MB issues**
EVGA 6600GT

NEW SYSTEM!!! ***Be here 11/19/07***
AMD Athlon 64 X2 6000+ Dual Core Windsor 3.0GHz Socket AM2
  **stock cooler**
ASUS M2N32-SLI Deluxe Wireless Edition AM2 NVIDIA nForce 590 SLI MCP
CORSAIR XMS2 2GB (2 X 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual CHL
Rosewill RX750-D-B ATX12V v2.2 & EPS12V v2.91 750W Power Supply
Western Dig. 300gb SATA 300mb/s HD
EVGA 8800GT 650mhz 512mb ddr3

I've been on the old system for several years. I build systems that last for 4 years+ playing the best of games. What do you think I will see after this upgrade? Post your thoughts and Ill keep you up to date on my build and testing! Are you an Over Clocker? Give me some clues on what you would like to see this setup do v.s. yours!
Think you can beat me out? Wan't screen shots to prove the win/loss. Just drop me a post on here. Just joined a few days ago and trying to get into the swing of things again.

As you can see, from my current build, its been a few years since I upgraded, and really got into it!!!!!Personally I would've gone with an Intel chip.

Even the E2140 is NICE enough, and you can overclock them like a *censored* (or so I've read).

But then again, for games and that you'd probably want a higher FSB, so the E4xxx range would've been a better line...but lets see how you find AMD dual core.Personally, I think you've made a bad decision (no offence)
Intel's Core 2 line far outperforms AMD's Athlon lineup - if you'd gone for, say, an E6550, it'd have far better performance and could overclock a lot better too.
The E2140 does indeed overclock fantastically, you can raise the FSB and it can rival the top of the line X6800, easily outperfoming the X2 6000+.
The best choice you made is the 8800GT, it's the card I would recommend.
But I'm sorry to say, I do think your CPU is a very bad choice.
However, on the bright side, your new rig will be a lot more powerful than your old one (just not as powerful as it could've been). Quote from: Calum on November 17, 2007, 05:53:40 AM

Personally, I think you've made a bad decision (no offence)
Intel's Core 2 line far outperforms AMD's Athlon lineup - if you'd gone for, say, an E6550, it'd have far better performance and could overclock a lot better too.
The E2140 does indeed overclock fantastically, you can raise the FSB and it can rival the top of the line X6800, easily outperfoming the X2 6000+.
The best choice you made is the 8800GT, it's the card I would recommend.
But I'm sorry to say, I do think your CPU is a very bad choice.
However, on the bright side, your new rig will be a lot more powerful than your old one (just not as powerful as it could've been).

E6600 all the way...

It depends on the purpose of the computer and the budget involved.
More cache will help performance in some applications.
Price wise, I'm seeing ~£40 for the E2140, ~£75 for the E4500, and ~£100 for the E6550.
Personally, I'd go for the E2140 for budget use, and the E6550 for other uses, rather than going in between and getting the E4500.  Not sure how the prices are outside the UK, but if they're similar to that then you can see what I mean.
Of course, that's just a personal opinion.
Basically, what I'm saying is that it depends on the prices involved, and the specific purpose of the computer.