Reputable brands for making CPU heatsinks at SPCR: Thermalright, Noctua, Scythe, Prolimatech. I guess "best" heatsink in terms of quietness is thermal performance at a certain noise level. Currently, many heatsinks offer comparable performance. Just take a look at some of the latest reviews.
BUT! a 2600k at stock speed really doesn't run that hot. You can easily keep it cool without using some of the heaviest & biggest heatsinks which can weigh more than 1 kg! For quietness, you should focus on the fan since the difference between the best heatsink and an adequate heatsink with the same fan may only be 5 degrees celsius. Take a look at this page for example: http://www.silentpcreview.com/article1171-page6.html
The temp increase for Thermalright Ultra-120 eXtreme Rev.C is 43 C, while it's 48 C for the budget Cooler Master Hyper 212+.
A good advice would be to buy a good heatsink which is bundled to a good stock fan. That way, you don't have to look for aftermarked fans.