You will find that alot of people talk out of their A$$. The key to good cooling also depends on proper case ventilation and room temps as well as the HSF, and proper installation of thermal compound. Their are many variables. My case sits inside my desk cabinet with little to no ventilation. How much are you looking to spend, how much do you want to OC it?
Thermal take Super Orb is good for moderate overclocking and is like $15, The new Thermaltake Volcano II is a good quiet cooler, and is fairly cheap.
The Alphas rock with delta fans. The Swiftechs are ok too. Just remember, Proper Ventilation, installation, ect..