The Thermalright twin-tower cooler is currently recommended in many DIY forums - and rightly so. In terms of cooling performance, it is on a par with the Noctua cooler, which costs a good twice as much. You don't want to run the dual fans above 1200 rpm, because then they quickly become loud...

With the Peerless Assassin 120 SE, Thermalright continues to offer a good overall package for a small budget. Despite its size, the CPU cooler can be easily and securely mounted on many different sockets and has a discreet black and silver look. The Peerless Assassin 120 SE is also available in white or with RGB fans, and at a price that is barely higher...