Nearly all the retail heatsinks I've seen from AMD lately are coolermaster units.
They are quiet, and they cool the cpu adequately even if they are the only fan other than the power supply in a case (just don't expect them to work well in a micro ATX case or something silly like that).
They are not the best heatsink out there for getting temperatures as low as possible, but, they keep the cpu within normal operating parameters, and that is all 99.9% of consumers out there want them to do. If you are an overclocker you should investigate other options.
Greg