Asus A8R-MVP and DFI LanParty nf4 SLI-DR Expert
AnandTech: Asus A8R-MVP: Mainstream Rocket. There is a new king of overclocking. For the last year or so, DFI has made the fastest boards with the overclocking.
Now the value oriented A8R-MVP along with the ATI Crossfire X1800XT is just amazingly quick.
Or, if you have lots of dough, the “DFI LanParty nF4 SLI-DR Expert”:http://anandtech.com/mb/showdoc.aspx?i=2620 at $210 is the board to get. It has amazing overclock if you have the right coolling. So some great choices here. Paired with an nVidia 7800GTX, it will scream.
Personally, the A8R-MVP makes some sense, but you have to get an ATI card for that to really rock, so on to that study.