I thought my sound card had bitten the dust earlier on, got me thinking about this. It's currently the oldest component of my PC, along with the case.
Both of them were purchased in January 2007, making them just over 3 years old - and in fact everything except my keyboard is newer than that! Sort of shocking to think, but there you go.
What about you?
And by the way, your main rig only. I know you've probably all got some ancient rig in the corner - scaryjim seems to run a home for hardware that's been cast out by the rest of society - but I'm interested to know about your main rigs, considering how often a lot of people seem to upgrade. Old cases I suspect, and maybe the odd floppy drive, but you tell me: what are the gems you just can't bear to part with?