The Gigabyte GA-7NNXP nForce 2 Ultra is supposed to be one of the best yet of the new Rev2.0/Ultra 400 boards.
I have the Asus A7N8X Deluxe rev1.04 and its rock solid though it has taken a while to get their with all the various bios updates over the months. The rev2.0 board is just as solid as they are mature products now.
The Abit Rev2.0 board is the one to go for if you like them, though I've heard stay away from their 1.x rev boards as they are very troublesome.
Their is also MSI,Aopen,Soltek,Chaintech and a few more to consider but I imagine if you stick to the Rev2.0/Ultra 400 boards you should not have any trouble.