Cooling performance tells only half the story. SilverStone's Heligon HE01 provided the coolest Core i7-3770K temperatures - in both the stock-clocked and overclocked tests - but there's an obvious downside to that cooling potential; its 2,000 RPM fan is pretty darn loud. The same could be said for Thermaltake's Contac 39, which spins up from relatively-quiet to annoyingly-loud as soon as the chip is placed under load.
Interesting to note, however, that some of these coolers do have bundled accessories to help limit noise output at the expense of cooling performance. The fan used in SilverStone's HE01 cooler has a toggle switch to alternate between performance and quiet modes, and moving to the latter reduces idle noise to 39.1dB. Similarly, using the low-profile adapter on NZXT's Havik 120 sees idle noise drop from 48.9dB to a more comfortable 45.3dB, and using Noctua's ultra-low noise adapters resulted in the NH-U9B's idle noise being reduced from 42.7dB to a quiet 39.1dB.
Arctic Cooling's Freezer 13 continues to be a pleasant surprise - it cools well and keeps quiet enough - but, if you're willing to put up with the size and weight, be quiet!'s Dark Rock Pro 2 offers the best mix of cooling performance and quiet operation.