If you want the best of the best, check out the cooler reviews at SPCR:
http://www.silentpcreview.com/Recommended_Heatsinks
SPCR ranks their heat sinks according to what provides the lowest temperatures with the lowest fan speeds for those requiring silent cooling setups. If you don't care about silence, then cranking up the fan speeds and installing a typhoon will only make the cooling even better.
The Ultra 120 extreme is one of the best. In the same class are the Noctua NH-U12P, and Xigmatek HDT-S1283. Prolima Megahalems is ranked as the best, but comes with no fan and is the most expensive heat sink you'll find on the market below water cooling.
Good luck!