I love how many of those machines are still around and still in use today. Low End Mac, for example, has a thriving user base, and there are still other groups about maintaining vintage Macs.
Unfortunately, the price on a lot of the older machines has gone way up, as people try to capitalize on the vintage trend.
I have a G4/800 iMac (the lamp one) that I still use, with Mac OS 9.2 on it.