As yours is the hardware voice of wisdom that I trust, I was hoping that you could help me with a question. I have followed your posts and setups as closely as my system will allow, but am interested in maybe getting it a little closer.
I currently run an HIS Radeon x1650pro 512Mb PCIe w/DVI/tv out,
And in my older system I have a Nvidea FX5500 256mb PCI with tv/s-video out.

With all that I've read about Nvidea being better for FSX (with drivers and Nhancer and such..), would it be a good idea to swap them? A GPU upgrade is still a little ways into the future thanks to current economic conditions and I thought I could maybe just optimize my system with what I currently have available on hand.

I am currently happy with my performance as I have it set up now, but if it can get better through this swap then I'm up for it. I currently get between 15-20fps in FSX with a decent amount of scenery(most sliders at 75%), and if I back off my weather, autogen, and traffic,(50% or less) I get 20 steady.

My specs (if needed for a reply)
AMD Athlon 64 x2 5400+ 2.8Ghz
x2Gb OCZ 800Ghz
X1650pro 512Mb PCIe
Asus M2A-VM-HDMI AMD690G chipset AM2 mobo
Thermaltake A4022 TR2-R1 CPU fan
Xion DAZL mid-T case with 500wPSU
80Gb hdd with XP(sp1,2,3)
500Gb hdd with FS9, FSX/Accel, and loads of addons & utilities
x20 HP lightscribe/DVD/CD burn drive
Tascam US-428 8-channel mixer/DAW/soundcard
x2 19"w.s. Acer monitors (1-DVI/1-VGA)
(if I forgot something you need to know just let me know )

Thanks for all replies and help!

Thanks for your reply. I've been looking at the 8800's on Tiger Direct, and also their AMD CPU's as that's what I'm stuck with on this board for now. My power supply is a bit overkill at the moment so it should be ok. I don't really mess with O.C. anymore(just not educated enough yet.)
Is there a certain AMD CPU that you would recommend for this setup, or should I just go for the baddest 4core that I can afford?

Thanks again for all your help and advice.(without you my computer would still run like S$%! )