Well, I haven't used fancy coolers for OCing coz I got no money for them. The cooler I'm using for my s939 system was cheap but its pretty decent. From that article, you can easily see how the big ones generally keep the cpu cooler especially under load. Tuniq tower is popular, but people always seem to have issues getting that thing mounted. Thermalright ultra 120 extreme is pretty nice, even the non-extreme (which is about $10 cheaper) does awesomely.