My current desktop (monitor on right in portrait mode) on my primary workstation that I built in the Summer of 2009. 3.5+ years of overclocked goodness - up to 4100MHz (edit: lol) on the ol' i7 920 w/2.66GHz stock clock. It's Noctua NH-U12P cooler has proven effective and quiet, but the SilverStone FT01B case I selected has one insanely hard to clean fan filter that also happens to be the main/largest one.
Last year, I added a SSD as a primary boot drive and I've swapped graphics cards at regular intervals (usually yearly). I did have a rear case fan go kaput, and it was removed without being replaced making for an even quieter system.
As a end-of-year treat to myself, I'm awaiting the arrival of this Nvidia GTX680 beast of a card: http://amzn.to/12xylaW
I'll admit that Far Cry 3 made me do it...the desire to run Ultra detail at 19x12 at 60fps is strong! It's so damn pretty!
I'll add that every PC workstation I have ever owned has been connected to a UPS (uninterruptible power supply) that insures a steady jiggle of electrons no matter how crazy the fluctuations are from my utility provider. UPS's are cheap insurance for your PC gear. So is an annual dusting of the case...so dirty!