The Asus P5W64 WS is usually the best and most stable overclocker for the E6600. Most top out around 450MHz. The Asus P5W DH is a nice board, especially now the cold boot issue has been fixed by bios. Mine topped out at around 425MHz. Other than that, the Badaxe 2 might be worth a look. It is super stable, but not user friendly for an overclocker. I had to mod my Badaxe 1 just to get the overclocking options to appear.