Thermalright Ultra-120 Extreme
It is basically an update to the Ultra-120 which is done by adding 2 more heatpipes. It will be released soon. But if you want a cooler that is out now, you can check out the non-Extreme version.
Here's a link to a page in an article that shows the graph of its cooling performace. You can see how it compares to other heatsinks (non-Extreme version is included too) and how it scales with clock speeds.
http://www.anandtech.com/casecooling...spx?i=2943&p=4
Note:
Thermalright doesn't include a fan when you buy their heatsinks so you can pair it up with a fan that suits your preference. AnandTech paired it up with the Scythe S-Flex SFF21F.
Seems like a few people are getting hyped up about the Cooler Master GeminII. But I won't recommend it yet as I haven't seen any reviews. I hope AnandTech does one so they can do a direct comparison to the other coolers.