I’ve used the word machines because in the UK at least retro gaming is as much about computers and electronic games as it is consoles.
So my favourites:
1970s Binatone Pong clone built into two controllers. One held batteries and the other the chip and RF modulator.
(Close second was an LED pool/snooker electromechanical game I can’t remember the make)
1980s ZX Spectrum. Just excellent gameplay (see Head Over Heels, Batty, Glider Rider etc)
1990s DOS Games too May to list
2000s GameCube. At the time under-rated but now appreciated for some excellent games