Intel stock HSF are adequet if they werent they wouldnt come with them. They are for the people who dont want to overclock or arent to technologically knowledgable to want to use thermal paste and third party sinks.
You will of course get better results (lower temps and or better overclocks) with a good third party cooler. But if you arent interested in overclocking or lower temps/noise levels the stocck HSF is great.
Thermalright ultra 120 is the best out there close 2nd is tuniq tower. If you want something good and cheap look at the Artic Freezer 7
Well, I didn't hear what I expected.
Right now in 2 identical systems with boxed E6550 Cpus - one with 3rd party unknown grease is running at 850 RPM and the on with original thermal pads is running at 1000 RPM. The single variable seems to be thermal paste.
Systems are running with same BIOS version and settings with changing the same hdd. IMO amazingly big difference! I can't believe it myself too but to do more precise tests isn't easy.