Contrary to popular opinion the mobo is the heart of the system. Without a good mobo the processor is just a fan cooled lump. Fortunately there are many top rated boards but serious research should still be done.
Here's a little research for you AMD types:
http://www.motherboards.org/rank/AMD...oard-rank.html
My non-AMD, it's in the mail board:
http://www.motherboards.org/articles...ws/1217_1.html