Thermaltake's Venus 12 is probably as good as it gets. It offers a lot of neat features and cools the CPU down extremely well. The only major downside is the noise level, which is always a factor in air cooling. The unit comes with 4 ways to control it. You can use the 3.5" control bus, a PCI control bus, straight up full throttle, or use a thermal sensor to detect the temp and adjust the speed accordingly.



Link: Xtremods