+1 for the 1200...I just switched from an Antec P182 SE, and my idle temps dropped 10 degrees celsius, with the 4 front fans on low, and the top and rear fans on medium...sitting at 4.05 GHz E8400 with idle temps of 25
On the high end, I can recommend my Lian Li ARMORSUIT P-80. It is roomy, light, well constructed and has great airflow. However, it is one of the most expensive stock cases out there.