Do you already have an AGP video card that you want to keep? In my opinion, that is really the only reason to get an Nforce3 mobo.
If this is your situation, I recommend that you have a look at the Gigabyte GA-K8NS series. I have the GA-K8NS Ultra. I have found it to be an excellent mobo. It is stable, reliable and performs well. It was also relatively inexpensive, and has a good manual, and was easy to setup.
Intel E6750...........PSN: ELBATROP
XFX nForce 650i Ultra
Patriot PC2-6400 8GB (4x2GB)
36GB WD Raptor
Samsung SyncMaster 931c
Samsung SyncMaster 750s
Windows 7 Home Premium 64