AMD Athlon x2 6400

didn't i just answer this? well anyway, most people are getting around 3.4ghz, mine tops out at 3.51

as for hintsink, tom (author Daniel Schuhmann) is comparing them with links on the main page
cpu cooler charts part one
cpu cooler charts part two

one that isn't included, which disappoints me cause i wanted to see how it stood up, is the tuniq tower 120. it keeps my overclocked 6400 (3.45ghz) to around 45 at full load. its big, but it works.

The Zerotherm Nirvana, beats the Tuniq tower, according to several reviews. According to Anandtech, it beats the Thermalright Ultra 120 Extreme(TRUE). However, THG seems to have rated it as poor due to difficult installation. No other reviews said this, so I'm doubting THG.