Known primarily for large and quiet CPU coolers, Noctua is not shy to attach a pair of 140mm fans to a chunk of metal. The NH-D15, announced today, can cool just about any current, mainstream or enthusiast CPU from AMD or Intel. It attaches to the CPU with a copper plate, which is connected to several copper heatpipes, which leads into two towers of aluminum fins. It is plated with nickel to prevent corrosion (I am not sure about the bottom).
As is common for these types of heat sinks, they are daunting to look at. Of course, that is not a bad thing, unless you have a very small case, but it might make you look at your stock fan differently. Noctua is claiming that their two fans spin at a maximum of 1500 RPM and a minimum of 300 RPM. This leads to a listed maximum noise value of 24.6 dBA, around the background noise of a quiet rural area at night.
The NH-D15 will be available mid-April for just shy of $100 USD.