I'm rather happy at the moment. I was playing around with my new Mac last night, seeing as Steam was released for it (Oh sweet free Portal). And decided to try gaming on my old iMac G4. This, be all means was the longest of long shots. It runs osx Tiger (Not usually supported for any newish games), has a 700Mhz processor and 512mb of ram. And finally, a dismal 32mb of video ram.
But, rather to my suprise, runs World of Goo absolutely perfectly, exactly the same as on my new iMac. Now, I know this isn't too amazing, being just a 2D puzzle game, but this computer was never built to game, especially 7 years after it was made.
And this leads me to my question of the day, what is the oldest system you still game on? Be it a computer, console, handheld. Anything!