But for Commodore I would say the C64GS is the worse mistake...
Indeed, making the C64GS is one of the strangest decisions ever made in computer history.
I really wish that the Amiga 500 would have had a game cartridge slot just like the C64. This would have made the A500 a 16-bit cartridge based console in 1987...one year ahead of Sega Megadrive that came out in 1988.
But no...C64, an old 8-bit computer gets a cartridge slot but a superior technology 16-bit machine is stuck with a floppy drive. And so Megadrive gets released and two years pass...and in 1990 Commodore decides that they too need a cartridge based game console. And so the C64GS is released to challenge the Megadrive and NES. But look: they just re-released the ages old C64 without the keyboard! And why? Because the C64 had the cartridge slot in it, and therefore it could be easily turned into a game console!
Or so they thought, because the C64GS was a massive failure...although theoretically it was a good idea, because the C64 had a massive game library, it had lots of good quality games, just like the NES had. But sadly most of those were in tape cassettes and floppy disks and totally incompatible with the cartridge based C64GS.
And then 3 years pass, and in 1993 Commodore finally decides that they need a game console based on Amiga technology, and so the CD32 is released. But soon after this the company goes bankrupt, so the CD32 never had a chance to shine.