What is the Loudest Component in Your PC?

As of now it is my Thermaltake Toughpower 650w PSU. Either the fan temp sensor is broken, or it is constantly overheating. What it is doing right now is rev up to 100% and then back to normal. It does it all day as long lol. Really annoying at times. I think I'll take it apart and see if it needs cleaned lol.

The next loudest would by far be the GTX 285. As long as the fan is under 50% it is silent.