Bryan Lunduke has a collection of old ads for what is still the best-selling model of personal computer of all time, the Commodore 64. No doubt it retains that title today on the basis of a number of technicalities, like PCs are atomized among many different makes that still all run the same OS, and people not considering an iPhone to be a computer somehow.
I’d like to draw your attention in particular to the ad for GEOS on that page, the early C64 windowed operating system that breathed new life into the system. In the end it was probably doomed due to a number of factors: Apple’s head start and much better marketing, the fact GEOS had to be booted from disk while Mac OS was partly ROM-resident, and a bit of clunkiness. But you can do rather a lot with GEOS all by itself, and it comes with a capable word processor in GeoWrite. GEOS, and its weird legacy, probably deserves a post of its own eventually.
The image above is for a fake ad, but it’s based off of an iconic, and slightly disturbing, television ad from Austrailia, Keeping Up With The Commodore: