I have a desktop computer back home that I built in 1998, it went through a couple of upgrades from my early adventures in overclocking (burned out a CPU and a video card) but it hasn't had any parts put into it in over a decade. Its still chugging a long fine and I still regularly used it before I moved. Currently it has XP and Gentoo Linux on it but its gone through lots of OS upgrades (98, 98 SE, 2000, multiple copies of XP and Linux distros).
The motherboard will die eventually and that'll be a sad day but until it does I just can't bring myself to get rid of the thing. Holds a special place in my heart and its the reason why I developed all the skill sets I have with computers. I'll probably re-use the case and monitor for other projects. The monitor is a 21 inch CRT that cost me an entire summers pay way back when.
Right now its mostly used as a display device for my old Dreamcast console, I made a VGA connector for it a few years ago to get the full resolution out of it (640x480 @60fps). Combined with the arcade sticks its just like playing fighting games with my buds in the arcades when we were kids. The only difference is we aren't dropping quarters into it constantly.