I just got an Arctic Cooling Freezer 64 and it is pretty good. Easyish installation, you don't have to remove the motherboard or apply new thermal compound (as it comes pre-applied). It is also far less expensive than some of the high end ones, I got mine of ZipZoomFly for $30 shipped on FedEx 2day air. It lowered my idle temps a few degrees C, but my load temps went down about 9C (around 49 to 40 from stock). Plus, it hasnt been on there long, so it may settle in and lower them more.