I've recently un-overclocked my pc and heres why:
I had my cpu (a 2.4ghz Core2Duo) clocked up to 3.0Ghz (333x9).
This was extremely stable and worked extremely well.
I didn't set my bios back to default because of stability or anything like that.
It dawned on me how noisy the fan was on my cpu, a Arctic Cooling Freezer Pro Fan.
It was running at 2,900 rpm, now i've set my cpu back to default its running at a mere 4,39rpm.
So the problem here must be a inadequate noisy fan.
Could anyone recommend a better, quieter fan?
Or is moving over to Water Cooling the only way to quiet my Pc.
Watercooling might be a little excessive for what you are wanting...a good air cooler would be more along the lines of what you are looking for. I know many people have good things to say about the Xigmatek, Arctic Cooling Freezer 7 and the Thermalright TRUEs.