Korg M1
Korg's 1988 sample-based synth that popularised the workstation: sounds, effects and sequencer in a single box.
The M1 played back short PCM recordings of real instruments and shaped them with filters and envelopes, which Korg branded AI synthesis. The novelty was the package: built-in digital effects and an eight-track sequencer meant you could write an entire song without any other gear. At roughly a quarter of a million units, it became one of the best-selling synthesizers ever made.
Its sounds dated the era. The M1 Organ preset defined early-nineties house, most famously on Robin S's Show Me Love, and its piano and choirs are all over the radio of the same years. The M1 set the template every major manufacturer's workstations followed for the next decade.