ASUS P6T-SE or the G-B EX58-UD3R motherboard
there both great boards the udr3 is crossfire and sli compatible with a bios update i recommend them both but im partial to gigabyte then asus
I love both Asus and Gigabyte. MSI is pretty sweet, too. I tend to go for Asus. Now you're really stuck!
We use a lot of both manufacturer's boards. We much prefet the Gigabyte for trouble free and long range performance. The ASUS are great for competitive gaming, but they are also a lot more trouble.
and what do you mean by trouble?
ASUS mobos are picky about RAM; certain RAM, such as OCZ kits, cause BSODs and the like. They only tend to accept Corsair, Crucial, and certain G.SKILL kits without any trouble. Also, sometimes the arrangement of NB heatsinks and other components on ASUS boards is odd, which sometimes leads to clearance issues if you want to install a large CPU HSF or other kinds of coolers.
Gigabyte mobos are, for the most part, free of such issues. They also generally have a larger selection of motherboards to choose from, at various price points.
I use Ultra RAM on my ASUS boards. Add that to the list of compatible RAM for ASUS.
i like gigabyte - all their products - cases, fans, motherboards - are great and i haven't had any problems. Can't say much for asus though, never bought any of their motherboards, although their flagship mobo is pretty sweet.