an35a ultra is the best price/performance board around period. ~$62 and has all the OC features you need. No raid, no sata, no frills fun. Whats best is it comes with a massive passive cooling solution on the north bridge unlike the other boards mentioned which 60mm fans are loud. As far as on-board sound, no humming or hissing is all I care about, and it has that feature.
My next choice is the A7N8X-E Deluxe, again because of passive cooling and rock stable, but it's almost double.
<----hates fans.