This is my current setup with 3dmark05 score for comparison:
Athlon64 3700+ (San Diego)
Corsair Value 2x512 @1T 2.5-3-3-8
Asus 7800GTX 256MB TOP 486/1350 (factory OC)
MSI K8N NEO4 Platinum (nForce4 Ultra Chipset S939 Mobo)
200GB WD SATA II
Aerocool Turbine 550W
3DMark05 = 8550 (with stock settings)
I have the same motherboard in my office computer with the A64 3000+ CPU and MSI 6600GT. This Board is non-SLI as i am not planning on using SLI. I have overclocked my Office computer a little bit, i.e., the CPU is overclocked from 1.8Ghz to 1.93Ghz (I simply upped the FSB to 215 from 200Mhz), and the 6600GT to 570/1140 from 500/1000. The Mobo is full of features such as dual GB Lan, SATAII, 4SataII ports, 2IDE, Firewire, lots of USB 2.0, 7 Channel AC97 sound with digital-out (optical and co-axial), basically all the nForce4 Ultra chipset features.
I would say that though my current boards are working stable and without issues (touchwood), I did loose one Board after one month of use. I am to date not sure if it was the board or the PSU because they both burnt out at the same time. So I cant really blame the board unless i was sure it was the board.
On the Toms Hardware Forums, I have read that Asus A8N nForce4 series boards and DFI Lanparty series are very good and stable. Specially, the DFI boards as they seem to be better at overclocking and are mostly free of all issues. I also hear that DFI is expensive as compared to the rest. In your budget of $150 I think you can easily get the MSI and Asus motherboards (non-SLI), maybe also the DFI.
You can also check
www.tomshardware.com for this article on S939 Motherboards
http://www.tomshardware.com/2005/05/...the_fast_lane/
My motherboard is in there as well, and I actually bought it because of the consistent high scores and recommendation by Tom's Hardware.
Hope it all helps.