Freezer 4 from AC does a brilliant job.
I am not gaming or OCing and once installed my Freezer, completely gave up the tempreture chase. Intel has a brilliant 'built-in' mechanism which will protect your CPU in the worst case scenario.
If you want to find an answer from the horses mouth, visit the Intel site for comprehensive temps information.
I also started with the stock cooler and found it anoyingly noisy.
I changed the cooler to a freezer just to realise that most of the noise was coming from my case fans and the PSU fans.
I think (have not checked in a while) my cpu idles at 40-42 C.
But as my case is utter crap I am sure I could do better with a proper case with some 120mm fans. 2400RPM is very good for a stock cooler. Mine used to spin closer to 3000. I would whole hartedly recomend the freezer which spinns at 2200 tops and hardly emmits any noise. But, CPU cooler is not everything.
It still need cooler fresh air from the outside. Do not overlook the case's tempreture and other componenets such as G card and memoery.
Best of luck!