Zalman CNPS7700-CU Ultra-Quiet CPU Cooler
I just fitted one of these to my rig. It's the 'flower' design, so there is slight overlap between the cooling fins on the cooler and the cooling fins on the nVidia chipset right next to the CPU. However, there is no contact if you do it right, and this cooler moves such a fantastic volume of air that the interior of the case (an Antec P180) stays nice and cool (about 35 under load).
It is a slight faff to put on though, and if you're wanting to use the little nVidia chipset fan, you need to put that on first.