Well I built an AMD64 with the MSI Neo2-Platinum board and I liked it. It had a good amount of BIOS options, enough to overclock if you wanted, a nice array of customization in other words. It also comes with what's called a D-link bracket that has 2 USB ports, but beyond that it has 4 LED's that if your computer doesn't boot up, those LED's will tell you what's malfunctioning in the computer by referring to the manual.
The ABit board I believe features a little tiny calculator type screen that displays a two digit code, like 9b, or something to that effect and once again you referr to the manual and it tells you whats wrong with it. On top of that ABit is also known for having a wide array of options in the BIOS for your customization needs.
MSI board has 8 channel audio I believe while the ABit has 7.1, but that's about all the info I know about them. I know nothing of ASUS and personally think it's a lousy board =/ Sry if I offend you, but the MSI board I worked with was great, and I've liked ABit thus far, and ASUS has let me down more than once, and I've seen quite a few threads regarding people having issues with their systems with that board..not saying it's necessarily the board every occasion, but I'm just sayin