In Neal Stephenson's "In the beginning was the command line" (http://www.cryptonomicon.com/beginning.html) essay, circa 2000:
Linux is an M1 tank coming in a free DYI kit. Bit hard to drive, but powerful.
Mac OS - the horrendously crappy 8.x or 9.x series, and any Apple user who doesn't think it was pants by 1999 is truly deserving of being called a fanboi - was a Vespa. Cool looking but crap.
Windows is a station wagon, IIRC. (Insert joke about Lada making station wagons?)
Unlike Neal's latter literary efforts, he more or less manages to get the point across without rambling on about the impact that the mating habits of arctic reindeers had on the dissemination of the printing press in Outer Mongolia or whatsuch.